P0133 code

[Al_S]

Hello all.

I have a 2004 Corolla that has had the P0133 code set. The PCM has been re-flashed last year under the TSB that addresses this issue. The code has not re-appeared for almost a year since.

The car's well maintained and I was wondering if there are any other things that can contribute to this before I have to replace the O2 sensor?

Thanks in advance.

Al

[mikered30]

Exhaust leak and dirty/bad MAF could cause it too, but most likely the front oxygen sensor.

[Al_S]

Originally Posted by mikered30

Exhaust leak and dirty/bad MAF could cause it too, but most likely the front oxygen sensor.

MAF = Mass Air Flow sensor?

Is that seviceable to clean or as a component replacement?

I also read about throwing the code due to intake manifold gasket leak from sub-freezing weather.

Any way of diagnosing this?

[mikered30]

Originally Posted by Al_S

MAF = Mass Air Flow sensor?

Is that seviceable to clean or as a component replacement?

I also read about throwing the code due to intake manifold gasket leak from sub-freezing weather.

Any way of diagnosing this?

MAF is serviceable: http://matrixowners.com/index.php?showtopic=65513

MAF cleaner is $7 at an autoparts store. You are supposed to disconnect the battery before cleaning and that will clear your CEL. It is very delicate do not touch it with anything besides the cleaner. How is your mileage?

Intake manifold is a possibility, when the CEL came on last time, was it cold out? To check for a leaky intake manifold gasket, spray the area around the intake manifold gasket with carb cleaner while engine is at idle. If you hear the engine rev, you found the problem.

[Al_S]

Originally Posted by mikered30

MAF is serviceable: http://matrixowners.com/index.php?showtopic=65513

MAF cleaner is $7 at an autoparts store. You are supposed to disconnect the battery before cleaning and that will clear your CEL. It is very delicate do not touch it with anything besides the cleaner. How is your mileage?

Intake manifold is a possibility, when the CEL came on last time, was it cold out? To check for a leaky intake manifold gasket, spray the area around the intake manifold gasket with carb cleaner while engine is at idle. If you hear the engine rev, you found the problem.

Yeah it's been cold!!! I'm north of you and it's been cold.

Thanks for the air leak tip - that'll be helpful in determining if there's a bad intake gasket.

I already cleared the CEL code with a basic scanner. Since it's going to be in the high 40's this weekend, it may interesting to see if the code re-occurs since there will not be much of a cold soak (at least it'll be above freezing overnight).