[gunnerxq]

So I have 29F4 and 29F5 codes. I replaced both post cat O2 sensors. Should I replace the precat O2 sensors. Or is it a cat issue and I need new ones?

The check engine light does come on but there is no loss in power.

[hassmaschine]

The codes tell you what they tell you. It either says post cat or pre-cat sensors.. it's one or the other, not both.

BTW, post-cat sensors can still affect long term fuel adaptations. They are *mostly* for emissions, but not completely ignored (because the DME tries to match emissions targets, too).

[gunnerxq]

Originally Posted by hassmaschine

The codes tell you what they tell you. It either says post cat or pre-cat sensors.. it's one or the other, not both.

BTW, post-cat sensors can still affect long term fuel adaptations. They are *mostly* for emissions, but not completely ignored (because the DME tries to match emissions targets, too).

So I'll probably need a new exhaust manifold correct? Should I risk it with a High flow cat?
And clearing adaptions probably won't do anything right?

[gunnerxq]

Actually can I somehow code it out with the Protool?
I'll try using a spacer first. Maybe that'll work.

[hassmaschine]

you can't delete errors with 'coding'. that is flash tuning.

you could try clearing errors resetting adaptations, it's not going to hurt anything.

[Volasko]

Could be MAF sensor connectors. Try removing and re-seating the connector a bunch of times to clean the contact points and I bet that will make the CEL go away. I went as far as replacing the connectors and it worked like a charm.

[gunnerxq]

Originally Posted by Volasko

Could be MAF sensor connectors. Try removing and re-seating the connector a bunch of times to clean the contact points and I bet that will make the CEL go away. I went as far as replacing the connectors and it worked like a charm.

Wouldn't I throw codes for the MAF then?

[Volasko]

Originally Posted by gunnerxq

Wouldn't I throw codes for the MAF then?

You would think so but I went on a troubleshooting journey to get to that solution. I don't have time to spell it all out here right now but the intermittent connection on the MAF created all these weird related codes like the ones your getting. I just kept getting the O2 sensor related issues that changed from one bank to the other at random. The best part of my suggestion is its free to try and super easy to do. Just unplug and plug the connector in a bunch of times to clean the contact points before your next longish drive. Don't clear the codes, but if after one or two drives the CEL goes away you know its this. The bad thing is you already spent the money on new O2 sensors. I was about to do the same before I miraculously came across this thread:

https://www.e90post.com/forums/showthread.php?t=905209

See page two for a link from PhaseP that ultimately lead to me fixing my issues as per the above. I know the codes don't exactly match up but at this point its worth a shot.

[hassmaschine]

Delete the MAF. Problem sovled.

[gunnerxq]

Originally Posted by Volasko

You would think so but I went on a troubleshooting journey to get to that solution. I don't have time to spell it all out here right now but the intermittent connection on the MAF created all these weird related codes like the ones your getting. I just kept getting the O2 sensor related issues that changed from one bank to the other at random. The best part of my suggestion is its free to try and super easy to do. Just unplug and plug the connector in a bunch of times to clean the contact points before your next longish drive. Don't clear the codes, but if after one or two drives the CEL goes away you know its this. The bad thing is you already spent the money on new O2 sensors. I was about to do the same before I miraculously came across this thread:

https://www.e90post.com/forums/showthread.php?t=905209

See page two for a link from PhaseP that ultimately lead to me fixing my issues as per the above. I know the codes don't exactly match up but at this point its worth a shot.

Hmm I'll give it a shot. Do you think I should put electrical grease?

[Volasko]

Originally Posted by gunnerxq

Hmm I'll give it a shot. Do you think I should put electrical grease?

I did when I replaced the connectors, can't hurt as far as I'm concerned. Since the fix I've been CEL free for a year.

[PhaseP]

I would also check exhaust leak close the O2 sensors.
Look for any black sooth at the first junction between header pipes and mid pipes that come right after the rear 02 sensors. Also any black sooth on any of the welds close to any of the 02 sensors.

[gunnerxq]

Originally Posted by PhaseP

I would also check exhaust leak close the O2 sensors.
Look for any black sooth at the first junction between header pipes and mid pipes that come right after the rear 02 sensors. Also any black sooth on any of the welds close to any of the 02 sensors.

Good point. The gaskets in the exhaust were changed because they were leaking badly.

I managed to put a 2.5" extender on the sensor that was giving me problems (the others were left alone.). And a different code for the sensor showed up about 2 weeks ago. The original code popped up a few days ago. So maybe the extender is too long? But at least the service soon hasn't showed up and managed to pass inspection. So progres I guess?

Does anyone know if I can gut the cats or get catless headers and put in O2 extenders so codes don't show up?

[hassmaschine]

Don't gut the cats. That will result in worse performance.

If you just want the codes to go away, get them deleted.

[gunnerxq]

Originally Posted by hassmaschine

Don't gut the cats. That will result in worse performance.

If you just want the codes to go away, get them deleted.

Codes or cats deleted?

[hassmaschine]

codes

[gunnerxq]

Originally Posted by hassmaschine

codes

How though? Is it possible with the Protool? I'm assuming it's not the same as clearing them.

Edit: I think I get it now. So if I were to get a new exhaust manifold and go catless BPC should be able to take care of any codes with a tune?