waulen2980

Got an out of state 07 GT stang with JBA shorties (legal), cold air (legal), but had a dyno tune where I think they messed with the cats. My old shorties were BBX (illegal) and failed sniff and visual of course.

My question- Do you think it might be worth it to go ahead try to test again since I have all legal parts now? I made the mistake before of testing without driving it around a bit. The tech said I obviously failed visual and too many hydrocarbons, but made no mention of the o2 sensor codes or anything.

If not, are there any paces to buy bolt on carb certified cats for 07 mustangs?

I'm still learning, so go easy on the jargon and technical stuff.

Matt's 95 Stang

It really depends on the tune. If the tune on the car is for the BBK cats and you take the BBKs off and add OEM cats then the tune will throw a CEL and you will fail the emissions test. You said you have have "all legal parts". Does that mean you put OEM cats on? If you did that did you change the tune to reflect the OEM cats and not BBK cats?

Matthew

waulen2980

No CEL, never did, and still don't. Gonna go for it one more time and if it still fails, at least I know what exactly needs to be done now and if not, saved myself some more headache. Thanks for the response!

Matt's 95 Stang

Well good luck. If you do fail come back here and we will see what we can do to get you to pass.

Matthew

waulen2980

Well, I passed the visual and computer, but failed the sniff test on HC and NO. That was a good point you made about reflecting tune for stock cats, didn't think of it. Yesterday, I hooked my sct tuner up and rolled it back to stock. I immediately noticed less power in acceleration, a higher idle rpm, and less rich of exhaust. I have not driven it enough as your suppose to after a tune to get it smogged (I believe 50-60 miles?) but hoping I can use my free retest to pass now.

Anything else you might suggest? Thanks for the help!

waulen2980

Rolled back to stock tune now I get a DTC P0174 System too lean on bank 2.

Should I clean MAH air sensors? If it was a leak wouldn't that have caused a code prior to stock roll-back?

Matt's 95 Stang

You know it would be best to create a new post in the S197GT section and see if they can help you. I honestly dont know what that code would be from.

Matthew