My car makes a bit of a extra humm now, and it comes from just underneeth my transmission:



I think around here, im guessing that is the cat?

But the engine seems to be fine when it is cold, but when I have been driving around a little, it starts to sputter, especially when I drive around in town at low rpm.

Is this cuz of some sensor in the exhaust? Or could I start to look for another source for this problem?

When I let the car cool down for a couple of hours, its fine again, but when I drive around, and set the car in Neutral, you can hear the idle is jitterish.

I don't think the problem is the manifold? I should hear extra noise in the engine compartment then?

 

O2 sensor is on the Y pipe could be that? do you see any rust around it? also there are two flange gaskets on the ypipe itself that could be leaking or the flex section could have rusted through? you will have to jack her up and take a look.

 

Its prolly the y-pipe flex section

 

Check coolant level....

 

You may have two unrelated problems.

The noise you hear from under the transmission could be a bad flex section (like sqibb said) or the o-rings at the y-pipe or gaskets on the cat might be bad.

As for your idle/stalling problem, you should first check your ECU for codes. If none come up, you have to do some testing and checking. I would probably start with the IACV and TB, along with sensors. A lot of the problems these cars have are with one of the sensors going bad. MAF, o2, coolant temp are frequent problems.

 

I had the car up and checked, it was some flexitube. Is it hard to fix? Im guessing I need to replace the O2 too?

Or should I just be looking for a complete new y-pipe?

 

if you were in the US I'd say get a complete performance Y-pipe.
but since you are in norway, you're probably better off just replacing the flex by itself.

 

I think I have this problem as well but my idling is fine. Sounds like a low buzz.

 

check your coolant temp sensor. my car had the same problem, when it was cool it ran okay but once it heated up the idle was funky and driving below 3k was sputtering alot. only a $20 part for autozone so doesnt hurt to change it.