So I just got a 96 OBW 2.5L Automatic and it's throwing a few codes, O2 sensors (P0135, P0141), knock sensor (P0325), and blocked EGR passage (P0400). I've read alot of threads about the P0400 code and almost dread the run around that may be associated with trying to fix the issue, but my engines performing quite poor so I am going to try everything to get it running better.

 

I Haven't tried anything yet, just getting prepared and I was wondering, if it comes to cleaning out the vac lines, is it ok to just spray carb cleaner down the tubes and let the engine spit the gunk out the exhaust or will that make things worse? Or option 3, is that not even how it would work and I'm talking out of the wrong hole? Haha. Theres a host of other problems I need to tackle but so far I think this will be the most confusing, so if anyone has any info, it would be greatly appreciated!

Pull the valve and make sure it's working properly and not blocked. Check the intake to make sure it's not blocked. Remove the hard line head to ERG and clean it if needed and check the hole into the head.

 

The Knock Sensor will make it run poor, so fix that one first.

Ah thanks. Hopefully the light stays off after I do that and clear the code, I've seen a lot of posts about the light coming back on after a few days even after getting a new valve and cleaning out every part involved lol hope that doesnt happen to me!