Damage to engine running without mufflers and cats?
#1
Damage to engine running without mufflers and cats?
Had a friend recently install long tubes on a 03 mustang GT and the car had previously had 2 cats and mufflers cut out and replaced with straight pipe.
Now it has no cats.
Says the car runs real rich, smells like gas and is now so lopey it sounds like it has a cam.
Its only other modes are 70 mm TB and plenum K&N filter, and an old tune that was done when he had 2 cats still on it.
Will it cause any damage? How long do you think it will take before anything bad starts to happen?
Now it has no cats.
Says the car runs real rich, smells like gas and is now so lopey it sounds like it has a cam.
Its only other modes are 70 mm TB and plenum K&N filter, and an old tune that was done when he had 2 cats still on it.
Will it cause any damage? How long do you think it will take before anything bad starts to happen?
#3
retune the car asap if its rich its prob fouling out the plugs causing it to run like **** but from my understanding the headers lean it out under WOT and the computer tries to over compensate for the lean condition by adding more fuel, id pull the plugs and i almost bet that they are all fouled
Last edited by S197_GTvert; 07-07-2011 at 12:55 AM.
#4
Rear o2 sensors will not affect how the car runs whatsoever, all they simply do is check to make sure the cat is working properly, the computer will not adjust or the car wont make any changes at all based on information from the rear o2s FYI, front o2s are the only ones that affect the car. OP: I would reflash the computer back to stock and see how it runs.
#5
UBERSTANG ,FYI ,i dont belive i said in that post that it would change the way it runs , he said the guy welded in straight pipes. it will just throw meaningless codes at him but it wouldnt hurt to put mills on. it doesnt seem like he planned for a tune with these changes to get that taken care of the right way so mills will stop those codes. FYI, i also said he should also get to a tuner asap and get it handled properly. but thanks for pointing that out to me needlessly in your sarcastic way.
#6
Funny, I took your reply and said the same thing in my head, he just got to it before me. If you meant it or not thats how you put it across. The only bit of sarcasm I caught was from your reply (y u mad bro?) Anyway, the car will smell rich once the cats are removed, thats common and does not mean it actually is dumping fuel. The OP's buddy might have other unknown issues. My guess is a vacuum leak
#7
UBERSTANG ,FYI ,i dont belive i said in that post that it would change the way it runs , he said the guy welded in straight pipes. it will just throw meaningless codes at him but it wouldnt hurt to put mills on. it doesnt seem like he planned for a tune with these changes to get that taken care of the right way so mills will stop those codes. FYI, i also said he should also get to a tuner asap and get it handled properly. but thanks for pointing that out to me needlessly in your sarcastic way.
Last edited by uberstang1; 07-07-2011 at 07:30 AM.
#9
And since were putting our highschool pants off I'd also like to mention he stated he has a tune which could also imply he has a hand held tuner which means he can simply turn off his rear o2s with the tuner instead of flushing money down the toilet buying MILs
#10
The O2 Transport Delay table values will need to be extended to accommodate the LT headers, this may account for the lumpy idle and the rich smell. Some handhelds let you select that you have long tubes and will make this correction.
The "rich" smell could also just be the stink that not having cats creates.
I agree that he should go back to the stock tune, also if not already done disconnect the battery for 5-7 minutes to reset the KAM...
The "rich" smell could also just be the stink that not having cats creates.
I agree that he should go back to the stock tune, also if not already done disconnect the battery for 5-7 minutes to reset the KAM...