So recently i swapped my exhaust manifold with a custom header, but the flex pipe on it is bad. I wont be able to change it for about a week. The car makes like a tractor noise when i drive, is it bad to drive for only a week? the check engine lights on btw.

 

I wouldn't drive a gazillion miles, but it should sorta be OK. If the exhaust leak blows exhaust onto the outside of the oxygen sensor (either one or both), that will mess up their measurement & throw the CEL.

For the rear sensor, all it does is measure whether your catalyst is still working. No problem.

If it blows exhaust onto the outside of the FRONT oxygen sensor, that will affect the air/fuel mixture, so in that case try to avoid driving too much / too far.

 

Okay, I checked the oxygen sensor today, and it looked in tact, and not melted or anything so I think its fine, but the only reason I'm concerned is because I smell gas when I'm at a stop light idlingor when I press the gas hard. Is that because some air is getting out beofre going through the cat converter?

 

Are you getting any Check Engine Light or any codes when you check it with a code reader?

WheelBrokerAng

 

When I mentioned exhaust blowing over the sensor, it's not about melting it.

The sensor actually measures oxygen DIFFERENCE from inside vs. outside, so exhaust blowing on the outside of the sensor will throw off the measurement.

O2 measurement will be high, so it'll think the engine is running lean, so it'll add more fuel.

 

Well I think it is in that case, I think it is because I smell straight gasoline when I'm idling or press the gas hard, but I just got my new downpipe so thanks for the advice anyway I appreciate it

 

Smell straight gasoline? Look for leaks. The O2 sensor doesn't have enough "authority" to make it really stinky rich, so maybe there's something else going on.

Otherwise, put on the new pipe & see if everything gets better. Let us know.

 

I just got my new pipe today, all I need to get is the bolts and gaskets. I will posts a comment of the results.

 

okay, so installed the stock manifold and downpipe, and every single problem i was having just dissapeared. it sounds like stock and runs like stock, no more tractor noise and gasoline smell. I will never change the exhaust manifold ever again. Thanks for your help jimblake, i appreciate it. and i have 1 more question... The CEL will turn off after a while because the problem is fixed right?

 

if you would have gotten a tune after you install you wouldn’t have the prob you hade. Tunes are key for aftermarket parts