P0453, P0420 and P0446

I seem to have gotten in the habit of trying to fix everything wrong with my 02 Silverado. I replaced the fuel pump to fix the hard starting issues, and then I replaced the vent solenoid with the relocation kit to clear the intermittent SES light. Well that cause the light to just stay on all the time. I got it scanned today and got back the codes: P0453, P0420 and P0446(which I believe is still there from the original vent solenoid). I am waiting for my truck to cool down so that I can swap O2 sensors post cat and see if the P0420 moves to bank 2. My question is what/where do I start with a P0453? The paperwork I got from the Zone said it is a fuel tank pressure sensor. Where is this located and how do I get at it? My guess is it is something I unplugged while changing the vent solenoid and I just lowered the front of the tank to do that.

Any help is greatly appreciated.

I seem to have gotten in the habit of trying to fix everything wrong with my 02 Silverado. I replaced the fuel pump to fix the hard starting issues, and then I replaced the vent solenoid with the relocation kit to clear the intermittent SES light. Well that cause the light to just stay on all the time. I got it scanned today and got back the codes: P0453, P0420 and P0446(which I believe is still there from the original vent solenoid). I am waiting for my truck to cool down so that I can swap O2 sensors post cat and see if the P0420 moves to bank 2. My question is what/where do I start with a P0453? The paperwork I got from the Zone said it is a fuel tank pressure sensor. Where is this located and how do I get at it? My guess is it is something I unplugged while changing the vent solenoid and I just lowered the front of the tank to do that.

Any help is greatly appreciated.

if you put the fuel pump , fuel tank O ring on wrong this would do it...got a big leak...in fuel tank...

I will have to check that. What would be the proper way to put it in/check it?
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I will have to check that. What would be the proper way to put it in/check it?
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drop tank/remove bed inspect for proper install and any lines cracked not connected wires connector issues etc....could also be the filler hose rusted thru etc....

OK. It will probably be a week or so before I can drop the tank since it is full. My guess right now is that the filler hose is loose from all of the dropping of the tank. The problem did not start until after replacing the vent solenoid so my thought is that is when it happened. I will post what I find.
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I seem to have gotten in the habit of trying to fix everything wrong with my 02 Silverado. I replaced the fuel pump to fix the hard starting issues, and then I replaced the vent solenoid with the relocation kit to clear the intermittent SES light. Well that cause the light to just stay on all the time. I got it scanned today and got back the codes: P0453, P0420 and P0446(which I believe is still there from the original vent solenoid). I am waiting for my truck to cool down so that I can swap O2 sensors post cat and see if the P0420 moves to bank 2. My question is what/where do I start with a P0453? The paperwork I got from the Zone said it is a fuel tank pressure sensor. Where is this located and how do I get at it? My guess is it is something I unplugged while changing the vent solenoid and I just lowered the front of the tank to do that.

Any help is greatly appreciated.

What mileage and what engine?

You need to clear codes and see what comes back.

Finding and having a Code 420 is like running into a big bad mean dude in a dark alley.:sarcasm1:



The Leading cause of code 420 is engine running rich or needing a good tune up.


http://www.troublecodes.net/articles/catfailure/




DTC P0420, P0421, and P0430 & P0431: Check Possible Cause Of Misfire DTC P0420 and P0421 indicate bank one catalyst system efficiency is minimum requirement. DTC P0430 and P0430 indicate bank 2-catalyst system efficiency is minimum requirement. Possible causes are as follows: Use of leaded fuel. Oil contamination. Cylinder misfire. Fuel pressure too high. HO2S sensor improperly connected. Damaged exhaust system component. Faulty ECT sensor. Faulty HO2S. Ensure ignition timing is correct. Retrieve all Continuous Memory DTCs. If misfire code is not present, go to next step. If misfire code is present, isolate cylinder and repair as necessary. Check HO2S Monitor DTCs If DTCs P0136, P0138, P0140, P0141, P0156, P0158, P0160, or P0161 were present in step 1), service as necessary before continuing. If none of these codes are present in step 1), go to next step. Check ECT Sensor DTCs If DTCs P0117, P0118, P0125 or P1117 were present in step 1), service as necessary before continuing. If none of these codes are present in step 1), go to next step. If any codes except P0420, P0421, P0430 and/or P0430 were present in step 1), service as necessary before continuing. If no codes except P0420 and/or P0430 were present in step 1), go to next step. Check Rear HO2S Wiring Harness Turn ignition off. Ensure HO2S wiring harness is correctly routed and connectors are tight. Repair or replace as necessary. If wiring harness and connectors are okay, go to next step. Check Fuel Pressure Turn ignition off. Release fuel pressure. Install fuel pressure gauge. Start engine and allow to idle. Note fuel pressure gauge reading. Increase engine speed to 2500 RPM and maintain for one minute. For fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article. If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, go to CIRCUIT TEST HC. Check For Exhaust System Leaks If exhaust system leaks, it may cause catalyst monitor efficiency test to fail. Inspect exhaust system for cracks, loose connections or punctures. Repair or replace as necessary. If exhaust system is okay, go to next step. Check For Exhaust System Restrictions Inspect exhaust system for collapsed areas, dents or excessive bending. Repair or replace as necessary. If exhaust system is okay, go to next step. Check Manifold Vacuum Install tachometer. Connect vacuum gauge to intake manifold vacuum source. Start engine and raise engine speed to 2000 RPM. Manifold vacuum should rise to more than 16 in. Hg. If manifold vacuum is okay, go to next step. If manifold vacuum is low, go to step 11). Leave tachometer and vacuum gauge connected. Start engine and raise engine speed to 2000 RPM. On a non- restricted system, manifold vacuum should quickly rise to normal range as increased RPM is maintained. On a restricted system, manifold vacuum will slowly rise to normal range as increased RPM is maintained. If manifold vacuum is okay, no indication of exhaust leak or restriction has been detected and testing is complete. If manifold vacuum is low or slow to respond, go to next step. Leave tachometer and vacuum gauge connected. Remove exhaust pipe from exhaust manifold. Start engine and raise engine speed to 2000 RPM. If manifold vacuum is now okay, fault is downstream from exhaust manifold. Reconnect exhaust pipe to exhaust manifold and go to next step. If manifold vacuum is still low or slow to respond, fault is in exhaust manifold or intake manifold gasket. Repair or replace as necessary and repeat QUICK TEST. Leave tachometer and vacuum gauge connected. Disconnect muffler/tailpipe assembly from rear of catalytic converter. Start engine and raise engine speed to 2000 RPM. If manifold vacuum is now okay, fault is in muffler/tailpipe assembly. Repair or replace as necessary and test-drive vehicle to verify elimination of symptom. If manifold vacuum is still not okay, fault is in catalytic converter. Repair or replace as necessary. Check tailpipe/muffler assembly for debris from catalytic converter. Test drive vehicle to verify elimination of symptom.

5.3 and 235k... Getting up there. So it sounds like another trip to the Zone is in order to get some codes cleared. I had intake gaskets replaced 18 months ago and was thinking that shortened the life of the converter. I will post which codes come back. Thank you for the help.
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You are welcome.
Mileage can be hard on cats but if keep tuned up good and not running rich they can last a long time.

The 5.3 is hard on fuel presure regulators.
Always check it.
As posted a cat code can be cause by several things.
REMEMBER Proper testing if the cat code comes back.
Good Luck.

UPDATE:
Well so far so good. I purchased a scan tool because AutoZone would not clear the codes for my(some law they said). I cleared the codes last night and now with 2 drive cycles(10-15mins each) I do not have any pending codes. So as long as that holds up I should be ok.

I do have a question, when you say tuned up, what does that entail? I know spark plugs, air filter and oil changes, but what else? Should I consider replacing O2 sensors as I do not know how old they are? Or should I just wait until they throw a code?

Thanks again for all the help, this place has been my most valuable tool in being a home mechanic.

UPDATE:
Well so far so good. I purchased a scan tool because AutoZone would not clear the codes for my(some law they said). I cleared the codes last night and now with 2 drive cycles(10-15mins each) I do not have any pending codes. So as long as that holds up I should be ok.

I do have a question, when you say tuned up, what does that entail? I know spark plugs, air filter and oil changes, but what else? Should I consider replacing O2 sensors as I do not know how old they are? Or should I just wait until they throw a code?

Thanks again for all the help, this place has been my most valuable tool in being a home mechanic.

TUNE UP IS A GOOD QUESTION.
And is often abused and shorted on what some call a tune up.

The good book calls for about 10 things on a major tune up.

Air cleaner and housing and air duck hose inspection.
Compression check.
Firing order check.
Fuel filter.
Fuel pressure check.
Idle speed.
Plug wires and cap and rotor and dist and spark check.
Ign timing on ones that it can be adjusted.
Spark plugs.
Clean and check battery and cables.
Valve adjust on adjustable valves.

Not included in a tune up.
I like to hook up a good engine capable scanner and look things over in there.
On the high mileage tune up where often a lot of things do not get ckecked or looked at untill 75-100 K or more.
I like to look belts and hoses and rad and coolant over good to

Most places skip compression check if no engine miss.
And Valve adjustment on ones that have hyd adjustable lifters with no noise.
If solid lifters valve lash should be checked.

After a code clear.
The code 420 may require running it 100 - 500 miles to reset.
Good Luck

Well, the P0420 came back but nothing else. My last major tune up consisted of spark plugs, air filter, and fuel filter. Am I able to adjust the valves on this engine? I only get the lifter noise for about 10 secs on startup and only when it is cold outside.

My next course of action it to check the fuel pressure regulator. I do this by removing the vacuum line and checking for fuel? I feel the engine is running rich as I have watched my MPG go from 18-20 to 13.8 on my last fill up. I will also switch post cat O2 sensors, even though this code is usually not a sensor, cause its easy and eliminates another possibility.

Is there anything I can do to eliminate a bad cat? I keep going back to that as the problem because Bank 1 is the side I had my misfire on with bad intake gaskets. I had the multiple cylinder misfire code for bank 1 for a couple months(3) before I could afford to get the intake gaskets replaced. If it does come down to replacing a cat, should I just replace them both? Also will universal units do or should I spring for the entire Y-pipe assembly?

If I have missed something, please point me in the correct direction.

Thanks again.

the cat problem is because you ran the engine for a good amount of time with those defects..I would replace both cat converters and the upstream O2 sensors....

the lifter noise on start up is usually the wrong oil and also cheap oil filters like fram etc...

get some high quality oil and wix , mobil1, or purolator plus oil filters...

using 1ounce of marvel mystery oil per quart of engine oil capacity over a few hundred miles will clean up the lifters . this will stop the lifter noises on start up ...but with crap filters the noise will come back..

What do you recommend for oil? I have been using Valvoline High Mileage syn blend 10w-40. I will use the different filter on my next change as well as the marvel mystery oil.

Thanks for the help.

What do you recommend for oil? I have been using Valvoline High Mileage syn blend 10w-40. I will use the different filter on my next change as well as the marvel mystery oil.

Thanks for the help.

you oil choice is damaging...10-40wt is a no no!!!
castrol 5-30wt or 10-30wt...mobil1 synthetic same wt's...

GM decades ago banned the use of 10 40wt oil/....provides poor lubrication.....damagesthe engine..so are you using the fram filters ???
this is now begining to make sense,,,,

Hey fram filters are what is predominantly available in my area. I have used them in all of my vehicles with no problems. Also, I was recommend by my mechanic to switch to 10w-40. I do not claim to know much about cars or engines, however I do try to take care of my stuff. I have always changed my oil in 4-5k intervals.

ANYWAY, on a different note, the FPR vacuum line was clean as a whistle, so it is looking more and more like a converter.

Hey fram filters are what is predominantly available in my area. I have used them in all of my vehicles with no problems. Also, I was recommend by my mechanic to switch to 10w-40. I do not claim to know much about cars or engines, however I do try to take care of my stuff. I have always changed my oil in 4-5k intervals.

ANYWAY, on a different note, the FPR vacuum line was clean as a whistle, so it is looking more and more like a converter.

As said 10W-40 oil and fram filters are a no no.



Heavy oil will not liberate newer engines in tight places.
Gm and Ford and Chrysler and import have all gone to 5w-20- 5w-30 on all engines.
Fram filters have been for 50 years and are still junk and engine killers.

Even AC Delco filters have gone down hill.
Wix oil filters are a good aftermarket filter carried by a lot of parts places.

On the cat code
The vacuum line test is good but does not rule out bad fuel pressure regulator or fuel pressure.
You need to get a fuel pressure gauge on it to test fuel pressure.

As for bad cat or 02 sensors Proper testing as I outlined in upper post will tell the problem.

Cheap aftermarkets cats will not do the job.
You get what you pay for.

The gm dealer factory cat or a top of the line direct fit from parts place is the way to go.

And after installation always make sure the engine is running right and not rich.
Rich running engine are cat killers.

so you think that these opinions are B/S ...I have no problem with that...since you have a computer use it to see for yoursellf what is proper to use in your vehicle..

also cut open the fram oil filters compare with the ones I recommend as I did ...then you will be believing my statements..

a mechanic recommended you use 10-40wt you should find another mechanic...if you live in the midwest there are many auto repair part stores that sell the recommended filters..

In your climate running 4-5,ooomi on a blended oil is too long...3-4,ooomi is best...or when the oil gets dark which ever come first..

some people think there saving money when the price determines there choices/maintenence intervals ,,in the end they always pay more..

Update: I replaced all O2 sensors and the Y-pipe assembly. The code has been gone for a couple days now. I have sourced a Wix oil filter and am going to replace the oil with 5w-20 Mobil1.

I tested fuel pressure and came up with 52 with key on/engine off and like 46-48 with engine running truck in park. I am a little dissapointed with this as my fuel pump is only 2 months old(delphi). Looks like the fuel filter may need replacing again(2-years old) or possibly a FPR that is overregulating?

Thanks for the help and for educating a kid like me.

Update: I replaced all O2 sensors and the Y-pipe assembly. The code has been gone for a couple days now. I have sourced a Wix oil filter and am going to replace the oil with 5w-20 Mobil1.

I tested fuel pressure and came up with 52 with key on/engine off and like 46-48 with engine running truck in park. I am a little dissapointed with this as my fuel pump is only 2 months old(delphi). Looks like the fuel filter may need replacing again(2-years old) or possibly a FPR that is overregulating?

Thanks for the help and for educating a kid like me.

What engine and engine code?

Testing a fuel pump requires a full fuel pressure test.

And remember the fuel pressure regulator controls engine fuel pressure.

5.3 non flex, I will have to double check but I believe it is a T code. I just found the procedure for fuel pressure testing, so I will do the entire thing and post results. So far it is running excellent and mileage is up 2-3mpg.

Thanks again.