rebel_logan

if this is in the wrong place please feel free to move elsewhere..

i have a 2007 mustang gt with sct x3 tuner, steeda cai, and dual flowmasters and i believe an x pipe(on car when bought so not sure exactly).

ok i have erased the data trouble codes 3 times since tuning the car and after about two days the codes keep poping up, they are the same codes every time something about catalyst pressure under threshold? what could that be and why does it keep poping up after being cleared via sct x3 tuner?

i bought the steeda cai and i am not sure if it is the 80mm or 90mm as sugested through am when getting new tunes.. how do i tell the difference and could it be throwing a code because i uploaded the tune for 80mm instead of 90mm or would that make any difference? thanks for any help or input! Logan

tx_zstang

What codes? Car have cats? If so, stock cats or aftermarkets?
Post up pictures if not sure.

808muscle

Name the codes.

neubstang

Could be as simple as a bad 02, but as stated above what codes is it giving you?

Nuke

Sounds like he could be running an O/R X and the tune isn't turning off the O2's.

neubstang

That makes sense, I think you can shut of two in the tune and still pass emissions?

SpartaPerformance

Did these issues 1st start when you loaded the tune? Then the problem is in the tune, whether it's due to an error in the software or error in your list of mods you told the tuner.

rebel_logan

sorry it has taken so long to reply back but have had som emergencys come up anyways i dont havent had time to jack up the car and look to see about the cats. the only tune issues i can think of is i dont know if my steeda intake is a 80mm or 90mm and im not sure about the cats or x pipe all i now for sure is that it has a steda cai and flowmasters.

the code that it threw was p4930 catalyst pressure under threshold (b2) and i has only thrown the one code the last 2 times it has had the check engine light.before it was throwing the p4930 code and a p4928 that said the same about catalyst pressure. any ideas or help would be great and also any advise on what i am lookng for when i do get time to look at cats and x pipe? thanks logan

rebel_logan

oh and check engine light was on before tune was installed but were gone after tune for about a week then they poped up i cleared them and they came back after two days and kept coming back every 2-4 days after.