I have an interesting question. i have a leak near or at the converter... my car is extremely slow...(it has a complete tune up no codes, dealer cant figure it out) but im wondering if the air leaking into the pipe might be messing up the fuel mixture... Just a thought because iv been trying to figure out why this car is so ridiculously slow...

 

I'm sorry, how would an exhaust leak effect air/fuel ratio at all?

I'll go ahead and take a possible shot: Could the readings that the downstream 02 sensor be different from the others and/or be the culprit?

 

thats what im talking about.. that book talks lots about exhaust leaks that they can cause problems.... but like this?

 

Exhaust leaks draw extra air into the exhaust system and the o2's see this and think that the motor is running lean. The ECU then dumps extra fuel to compensate and you end up running rich, which kills low-end power and MPG.

 

what he said!

 

...interesting

 

My CEL states that I can have an exhaust leak. The CEL also says that the air/fuel ratio is bad and my left bank is running lean.

 

I have TOO many exhaust leaks...just waiting to unpack from college (parents orders) before I start tearing at my car again. I have a WSP y and 2.5" catback w/ 5th Gen muffler sitting at my house as of right now.