Two weeks ago I change my exhaust, with O2 sensor extenders.
For a week no issues no CEL. Last week the car is running really rough and stalling at idle, no CEL.

Do I need a tune after a cat back? or is something else going on?
What step to do next? I have a Durametric.

Do I unplug battery to reset the DME or can I reset with the DME somehow? How?

TIA

 

Are you running the stock cats?

 

No newer High Flow 200 Cel

 

If you changed the cats then the exhaust system is not "cat back"...so that might be the first place to look. Even though no CEL you might have some codes - your Durametric can read those if present. Check the O2 extenders also.

 

I have a B1510
Air mass (HFM) ahead of throttle valve - implausible
Implausible signal

 

Try cleaning your MAF - lots of posts on how to do this. Search MAF cleaning.

 

Thanks, I'll do that after I go buy the T25 Torx Plus socket,

 

Similar probs here:-
I changed my exhaust too about 2 weeks ago, (europipe) had cel lights so changed both pre cat lambbda's. Cel now gone but i get B1510 error code, maf related. cleaned both maf's and cleared fault but has come back on after couple of days. I think i need a new one. its the left one when your looking in your engine bay that's got something wrong with it on my car. Let me know how you get on pls...

 

Cleared code and cleaned mafs, car runs better. I drove it to work today so far so good.

 

I used to get that code all the time after hard pulls and then had 2 MAFs fail in a week, now MAFLESS

 

happened to me once and they replaced the MAF

 

Can you go MAFLESS? If so how?

 

How can you tell which MAF is bad or do you just change both?

 

2nd day after clearing code, I get a CEL. Will read code tonight.
Think maybe the MAF s are going? Do I just replace both?

 

My left maf looked dirty when i cleaned my ones so guessing its that one thats's dodgy.