Brainbuster for the pros
stearnski
08-23-2005, 05:56 PM
99 Prizm, CEL light comes on in warm weather and disappears in the winter.
CEL codes:
P0441 Evap emission control, Purge flow fault
P0446 Vent Circuit Malfunction
This has gone on over a year, no other problems. Gas Mileage is excellent (35-40mpg).
CEL codes:
P0441 Evap emission control, Purge flow fault
P0446 Vent Circuit Malfunction
This has gone on over a year, no other problems. Gas Mileage is excellent (35-40mpg).
johnholl
08-24-2005, 11:12 AM
In the winter the ambient temperature is low enough that the OBD doesn't run the diagnostic to set the codes. Its' nothing to be concerered about, with 2 exceptions:
1 Your state of residence requires emissions testing
2 With the MIL on continiously, ou will be unable to tell if other unrelated problems arise.
This code sets if the canister purge valve malfuntions, canistor,or the lines are leaking, or the Fuel tank pressure or canister switching valves, fail during self-diagnostic testing. I doubt if it's a gas cap problem.
The canister, and its valves, are located behind the rear axle, the purge valve is under the hood.
I haven't been able to get it working correctly on mine. And I'm an engineer. The Canister and valves are expensive, so have a plan before you have someone replace components willy-nilly. Because the codes will not comeback for a half a week, if it hasn't been repaired correctly. [drive cycles]- long after your check has cleared that you gave the garage.
1 Your state of residence requires emissions testing
2 With the MIL on continiously, ou will be unable to tell if other unrelated problems arise.
This code sets if the canister purge valve malfuntions, canistor,or the lines are leaking, or the Fuel tank pressure or canister switching valves, fail during self-diagnostic testing. I doubt if it's a gas cap problem.
The canister, and its valves, are located behind the rear axle, the purge valve is under the hood.
I haven't been able to get it working correctly on mine. And I'm an engineer. The Canister and valves are expensive, so have a plan before you have someone replace components willy-nilly. Because the codes will not comeback for a half a week, if it hasn't been repaired correctly. [drive cycles]- long after your check has cleared that you gave the garage.
stearnski
08-25-2005, 09:05 PM
What is the purpose of the canister and is it easy to find/inspect?
I have been noticing that it ocassionally sounds like I have an exhaust leak when I accelarate. I inspected exhaust system and couldn't find any holes. Could this be related?
I have been noticing that it ocassionally sounds like I have an exhaust leak when I accelarate. I inspected exhaust system and couldn't find any holes. Could this be related?
johnholl
08-30-2005, 11:17 AM
The canister stores and burns fuel tank vapors
The canister is behind the rear suspension. It's a pain to diagnose electrically
I have the same exhaust leak sound on my wife's car on acceleration. It may be the manifold, or exhaust system. Also check to see if the spark plugs are tight.
The canister is behind the rear suspension. It's a pain to diagnose electrically
I have the same exhaust leak sound on my wife's car on acceleration. It may be the manifold, or exhaust system. Also check to see if the spark plugs are tight.
jrehm
11-25-2005, 11:34 PM
My wife's '99 did this now and then. Never consistent enough to determine what was really causing it and I didn't want to start changing expensive things unless I could be sure it would fix it.
She took it for an oil change at a local quick change (read that quick steal) place and they talked her into a rubber washer for the gas cap ($10). Didn't have the problem for a while, so she was convinced that she knew what she was doing and I was an idiot for being skeptical. But, the problem eventually returned.
She took it for an oil change at a local quick change (read that quick steal) place and they talked her into a rubber washer for the gas cap ($10). Didn't have the problem for a while, so she was convinced that she knew what she was doing and I was an idiot for being skeptical. But, the problem eventually returned.
johnholl
11-28-2005, 11:23 AM
My wife's '99 did this now and then. Never consistent enough to determine what was really causing it and I didn't want to start changing expensive things unless I could be sure it would fix it.
She took it for an oil change at a local quick change (read that quick steal) place and they talked her into a rubber washer for the gas cap ($10). Didn't have the problem for a while, so she was convinced that she knew what she was doing and I was an idiot for being skeptical. But, the problem eventually returned.
Yeah, I wonder how much money is being made by garages [including GM, Ford] selling people gas caps and then clearing codes. Because they are basicaly troubleshooting via hit-or-miss.
Blame the FED's They are the ones that made the manufacturers incorperate these diagnostic systems.
And then the mechanic is told by the computer the problem could be A,B, or C. After the CORRECT part is replaced, the mechanic must the put the car through enough drive cycles to see if the problem is indeed corrected. Meanwhile the consumer pays for parts he or she may not have even needed to replace.
John,
Electronic Technician
ps: It may be the canister, or the tank pressure sensor, or even the CPU. If she doesn't need the light off for inspection leave it be.
She took it for an oil change at a local quick change (read that quick steal) place and they talked her into a rubber washer for the gas cap ($10). Didn't have the problem for a while, so she was convinced that she knew what she was doing and I was an idiot for being skeptical. But, the problem eventually returned.
Yeah, I wonder how much money is being made by garages [including GM, Ford] selling people gas caps and then clearing codes. Because they are basicaly troubleshooting via hit-or-miss.
Blame the FED's They are the ones that made the manufacturers incorperate these diagnostic systems.
And then the mechanic is told by the computer the problem could be A,B, or C. After the CORRECT part is replaced, the mechanic must the put the car through enough drive cycles to see if the problem is indeed corrected. Meanwhile the consumer pays for parts he or she may not have even needed to replace.
John,
Electronic Technician
ps: It may be the canister, or the tank pressure sensor, or even the CPU. If she doesn't need the light off for inspection leave it be.
n1ckml007
07-14-2006, 12:20 PM
I had to get the canister filter replaced on my 1999 Prizm to pass inspection. It is located under the rear axel.
jrehm
07-14-2006, 03:06 PM
I had to get the canister filter replaced on my 1999 Prizm to pass inspection. It is located under the rear axel.
I'm starting to wonder if my wife's doesn't need this. The check engine light is on most of the time now and comes back fairly quickly if I clear the codes. I'm getting a EVAP Emission Control System Purge Flow Fault code set. Haven't had time to check it out yet though.
I'm starting to wonder if my wife's doesn't need this. The check engine light is on most of the time now and comes back fairly quickly if I clear the codes. I'm getting a EVAP Emission Control System Purge Flow Fault code set. Haven't had time to check it out yet though.
n1ckml007
07-15-2006, 11:55 AM
The codes I had prior to inspection were PO441 and P0446. My check engine light was on consistantly. The notes on my shop write up are "EVAP INCORRECT FLOW AND VENT CONTROL PROBLEM. TESTED THE EVAP VENT VALVE AND IT IS NOT WORKING. SOLD AS CANISTER AND VALVE ASSEMBLY"
The cost was $272.35 for the part and $75 for and hr of labor.
The P0446 was thought to be a related to a broken O2 stud, which was replaced with the gasket. The cost to fix that was $8.95 for the gasket and $105 for the labor.
The cost was $272.35 for the part and $75 for and hr of labor.
The P0446 was thought to be a related to a broken O2 stud, which was replaced with the gasket. The cost to fix that was $8.95 for the gasket and $105 for the labor.
jrehm
07-16-2006, 06:09 AM
Yeah, I wonder how much money is being made by garages [including GM, Ford] selling people gas caps and then clearing codes. Because they are basicaly troubleshooting via hit-or-miss.
Blame the FED's They are the ones that made the manufacturers incorperate these diagnostic systems.
And then the mechanic is told by the computer the problem could be A,B, or C. After the CORRECT part is replaced, the mechanic must the put the car through enough drive cycles to see if the problem is indeed corrected. Meanwhile the consumer pays for parts he or she may not have even needed to replace.
John,
Electronic Technician
ps: It may be the canister, or the tank pressure sensor, or even the CPU. If she doesn't need the light off for inspection leave it be.
Light needs to be off, now anyway. Problem is they don't look for just the light. They check the stored codes. I can blow out the codes before it's inspected, but no guarantee they won't come back when the motor is started and it looks a little suspect if I say "let me in there for a sec before you hook up to the diagnostic connector". But, then again, most inspection guys (as long as it isn't state inspection stations) aren't too anal about it.
I have a place I always go for inspections because the guy will 'work with me', but I've found that it's best to pick a place that does inspections that also doesn't do the types of repairs your car is likely to need in case of failure. For instance, there's muffler shops around here that will do inspections, but they are no where prepaired to start swapping out engine parts and such. So, they aren't as likely to be sticklers on some things simply because they don't stand to make money from it.
Blame the FED's They are the ones that made the manufacturers incorperate these diagnostic systems.
And then the mechanic is told by the computer the problem could be A,B, or C. After the CORRECT part is replaced, the mechanic must the put the car through enough drive cycles to see if the problem is indeed corrected. Meanwhile the consumer pays for parts he or she may not have even needed to replace.
John,
Electronic Technician
ps: It may be the canister, or the tank pressure sensor, or even the CPU. If she doesn't need the light off for inspection leave it be.
Light needs to be off, now anyway. Problem is they don't look for just the light. They check the stored codes. I can blow out the codes before it's inspected, but no guarantee they won't come back when the motor is started and it looks a little suspect if I say "let me in there for a sec before you hook up to the diagnostic connector". But, then again, most inspection guys (as long as it isn't state inspection stations) aren't too anal about it.
I have a place I always go for inspections because the guy will 'work with me', but I've found that it's best to pick a place that does inspections that also doesn't do the types of repairs your car is likely to need in case of failure. For instance, there's muffler shops around here that will do inspections, but they are no where prepaired to start swapping out engine parts and such. So, they aren't as likely to be sticklers on some things simply because they don't stand to make money from it.
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