Ford Mustang Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
149 Posts
Discussion Starter · #1 ·
94 gt all stock except has h-pipe w/o cats. gonna buy new x-pipe with high flow cats, my question is will it pass emmissions test? do i need o2 sensors? thanks in advance for any feedback.
 

·
Registered
Joined
·
46,010 Posts
As long as the engine is in good running condition, if you put cats back on it, it should pass. Put them on, run the engine for a few minutes, and then check to see if you have any codes. You shouldn't, and the O2 sensors need to be replaced between 50,000-60,000 miles. If it's been longer than that, replace them.
 

·
Registered
Joined
·
149 Posts
Discussion Starter · #3 ·
ty eagle for the input. are the o2 sensors still located on the pipes? dont think i have any on it now. i just bought the car. if i dont HAVE to have them i wont get em, but didnt know if i need for emmision test. thx again.
 

·
Registered
Joined
·
46,010 Posts
Oh yes, you need them for emissions testing. They're in the pipes, right under the header collector. They tell the computer how much oxygen is in the exhaust gas, and the computer will compensate with the air fuel mix.
 

·
Registered
Joined
·
149 Posts
Discussion Starter · #5 · (Edited)
so if i dont have any it will just fail again, correct? also this would explain a low rough idle.:headscratch:
 

·
Registered
Joined
·
341 Posts
I see you are in Tennessee. Williamson county? Davidson? I went thru the process with my '93 in Williamson county. First thing they do a visual for the presence of cats. No cats = automatic flunk. Once you get cats on the car and get your O2 sensors in place, then you will likely pass. Make sure the car is good and HOT when you take it in. DON'T turn the engine off before the test. For some reason, doing that dumps a bunch of raw fuel into the exhaust & it won't pass. Mine flunked with brand new cats because I did that. If you still flunk with cats and senssors, move your timing back to the factory 10 degrees and dump some alchohol in the tank. My car has an adjustable fuel pressure regulator. I reduced the pressure by 5psi. That leans out the motor. Passed with no trouble.
 

·
Registered
Joined
·
341 Posts
No not rubbing alchohol. Use a couple cans of DryGas type. Helps it work better if your tank is low. The alchohol leans out the mixture.
 
1 - 9 of 9 Posts
Top