That's actually part of the radiator fan shroud. And it wouldn't cause an O2 sensor code. As for fixing it, replace it or tape would do the trick. Thank you. So as far as the O2 sensor code (PO131 and PO137) is concerned....if I've already replaced the downstream sensor, I assume I should check for...

Can someone please identify this part (I'd call it an air box)? I'm still getting codes for an O2 sensor, which I replaced, but I'm wondering if this cracked part is causing a vacuum leak that is triggering a code for the O2 sensor. Any suggestions on how to repair this thing? Thank you! Todd

I believe the knock sensor is down near the oil trap, right? I didn't touch it and I don't remember seeing any broken wires. Does it have an electrical connector where it plugs in? I should tell you that this was the code I got BEFORE servicing the PCV. Since the check engine light is still on, I'm ...

Didn't you recently replace the PCV system? I mentioned it in another reply, but if you could consolidate your threads, or at least provide links to them we could follow what you have already done and help with the puzzle that is your '94 T5 Yes I did recently replace the PCV system. I'm not sure h...

Okay I will have to go back and get the actual codes. Heard of a MAF sensor, but I had never heard of a knock sensor either. That's why I'm trying to find answers in the forums.

Well I suppose the easiest place to start would be to clean the MAF sensor.

Good job. I did that the first 2 times, but found the intake manifold was not flush, thus creating a big vacuum leak.

I have a check engine light that says it is either my knock airflow sensor or my mass airflow sensor. The vehicle drives fine for me, but I would like to get the check engine light turned off. What is my first step in resolving this issue? Thanks.

Anybody have any tips on how to reinstall the EGR valve into the intake manifold? I found you pretty much have to bolt down the intake manifold and then try to get the EGR valve attached. The pipe is just a bear to manipulate. It took me hours and I was somehow able to reattach it, but it seems like...

Here's the update.... I reinstalled the intake manifold gasket. I put some ATV on it and along the top. But I think the most glaring issue that I really butchered reinstalling the fuel injectors. The lower fuel injector seals were wrapped around the fuel injectors and I didn't even see them. They we...