Ok, to make a long story short. I ran my 2001 Denali into an overflowing lake. Water was everwhere and clogged the air filter.

Limped home, replaced air filter but at the same time decided to clean the throttle body since it was filthy. When I put everything back together, forgot to plug in air flow meter and turned ignition on.

Now it idles lumpy and check engine light on. Checked codes, engine misfire and right bank lean? If I drive the car on the highway at anything other full throttle ALL IS OK.

If I hit full throttle for 10sec or so, the car goes back to idling lumpy and missing. I have changed plugs and wires.

Any ideas what can cause this problem?

Thanks,

Anthony

dirty Mass air flow senesor is one possibility.

Ok, to make a long story short. I ran my 2001 Denali into an overflowing lake. Water was everwhere and clogged the air filter.

Limped home, replaced air filter but at the same time decided to clean the throttle body since it was filthy. When I put everything back together, forgot to plug in air flow meter and turned ignition on.

Now it idles lumpy and check engine light on. Checked codes, engine misfire and right bank lean? If I drive the car on the highway at anything other full throttle ALL IS OK.

If I hit full throttle for 10sec or so, the car goes back to idling lumpy and missing. I have changed plugs and wires.

Any ideas what can cause this problem?

Thanks,

Anthony


you didnt suck in water did you!! :nono: lol

u ever check ur oil for the hell of it? make sure its not a creamy color.

dirty Mass air flow senesor is one possibility.

I cleaned it out with carb cleaner but did not help.

Thanks for the response.

Anthony

:rofl: you didnt suck in water did you!! :nono: lol

u ever check ur oil for the hell of it? make sure its not a creamy color.

Luckily no water went into the motor, that was saved by the way GMC designed the intake!

I've heard that it could be related to a bad 02 sensor.

I'll update when I get it fixed.

Anthony

O2 sensor would set off the Check Engine light 90% of the time. Im not sure I would trust carb cleaner on the MAF. I think it might leave behind a slight residue. I would use something for electronics. Like electric motor cleaner, contact cleaner, or CEN makes MAF cleaner.

O2 sensor would set off the Check Engine light 90% of the time. Im not sure I would trust carb cleaner on the MAF. I think it might leave behind a slight residue. I would use something for electronics. Like electric motor cleaner, contact cleaner, or CEN makes MAF cleaner.

I agree. If I only knew that then. Turns out that when the issue happens at idle, the entire right side of the motor is not firing for some reason. We called one of our friends at the dealer and he said if ONE injector was bad, that entire side would not fire.

Weird.

Anthony

I agree with interceptor - the MASS sensor needs to be cleaned with intake cleaner. I never heard about 1 injector causing the whole side to fail. I know I got my MASS wet and I paid for it for some days until it dried.

O2 sensor would set off the Check Engine light 90% of the time. Im not sure I would trust carb cleaner on the MAF. I think it might leave behind a slight residue. I would use something for electronics. Like electric motor cleaner, contact cleaner, or CEN makes MAF cleaner.

You were right. It was the front 02 sensor on the right side. I had a shop change it ($150 part) and the truck is back to normal again. It was the 02 the entire time.

Thanks!!!

Anthony