i had to cut the exhaust down right after the o2 sensors to work on the driveshaft. i was able to weld up the bottom when I put the exhaust back up, but on top it leaks some....car sounds loud. Deff. needs fixed. No check engine light was for days driving it like that but today on the highway i got the check engine light come on. codes are as follows:
p0432, po441, po332, po411, po422
Could a exhaust leak cause this? I'm assuming the cats aren't getting hot enouph since there is leak right after them on both sides right by the o2 sensors......as for the knock sensor, maybe due to the noice of the exhaust leak?

Thoughts suggestions?
Thanks,

This is on a 99 2.8 automatic.

 

Did you cut into the cat? Did you do both sides? Its easier to cut after the flex and reclamp it

 

No, I cut after the O2 sensors. Way past the flex parts.
Car runs fine and idles fine. Not sure if some of those codes were there before but all of a sutton while driving it came on. Thoughts?

 

Sounds like you've got bad cats or possibly some vacuum leaks. Got a VAGcom? Log the O2 sensors, MAF, and adaptions and post them here.

Other possibilities are stuck-open N80 (evap. Purge) or leaks in the secondary air injection system.

 

No way to log anything. If it wAs vacuum related wouldn't it run bad or idle bad?
As for cats being bad, just weird how they would fail at the same time.
Any input on the knock sensor? That one has me worried the most.

The secondary air pump, that's emissions related as well right?

 

Does the 99 2.8 even have a SAI pump?

 

I wouldn't think so...for what ya know? Is there a possibility that you damaged your 02 sensors when you welded back your exhaust? That might be a cause for them giving you a scewed reading...Did you try just clearing the codes and see which comes back?

 

Good question. 99 1.8ts don't. I think 98 and up 2.8s do.

If he had a stuck open N80, it could cause a secondary air fault due to a leak in the vacuum system. Its a long shot with all those codes, but it's easy to eliminate the possibility. Apply 12v to the N80 and see if it clicks. Then check the ground and make sure its not shorted.

 

Car ran find all week, just during highway driving it came on.
I don't think I was very clod to the o2 sensors. Certainly didn't touch them or anything.

I'll fix the leak and clear the codes.

Any idea what would cause the knock sensor code?

 

That one has me a bit confused. I would definitely clear that and see if it comes back.