Why did this happen?

[d98gt]

I had my stock midpipe taken off due to it having 6 cats, which is totally uncalled for

I put on a pipe which has two cats, after a few bad words due to the passenger side where the pipe connects to the manifolds, one of those bolts is a major PITA

After the install after I drove a few miles I threw a check engine light, which was expected being that I didn't have mil elim. installed. I drove around for probably 3-4 hours with the check engine light on and it wasn't all that bad, however today when driving, I got on it a bit and the check engine light went off. The getting on it and it turning off wasn't probably related, however, why the hell would the CEL go off after 2 days of driving with it on?

 

[exindust]

did your battery die?

 

[d98gt]

Nope, I was just driving home from class today on the way to the shop and when I passed someone the light just turned off. I've drove the car about 35 miles since then and it hasn't returned

 

[Dope 97GT]

i would say f' it and not complain about NOT HAVING a CEL. I have one and its a major PITA

 

[d98gt]

I'm not complaining by any means, just curious of why it happened

My luck the damn bulb went out

 

[Mustang5L5]

it will come back eventually

 

[thomas91169]

^^^yep

when you got on it the a/f must have dipped into a range that the rear o2 sensors liked seeing, so the ecu got happy thinking you put your cats back and took the code away.

Though it has no effect on performance, the rear o2's job is to make sure the cats are working properly, and is merely a OBDII Emissions related component, not a sensor that can affect fuel/ignition parameters.

 

[d98gt]

Yeah, i'll just buy the cheap splice in mils and get it over with. As for the time being, I'll enjoy driving without the annoying bright light

 

[COramprat]

Yeah, i'll just buy the cheap splice in mils and get it over with. As for the time being, I'll enjoy driving without the annoying bright light

Get a piece of black electrical tape to stick across it if it comes back on before you splice the O2 sims.

 

[Dusstbuster]

My Hydraulic Control Module for the ABS system in my car is fried so I've had the fortune of staring at the ABS light for 2+ years. Add on the fact that 96's have crappy oil level sensors and like to burn oil AND that it doesn't like the aftermarket intake and there are some weeks where i'll be driving with an ABS, CEL, and LOW OIL light all at once...it is very annoying.

 

[CobraRed_96_GT]

wait u replaced it w/ a pipe that has 2 cats? in this case you still have holes for the two o2 sensors and there shouldnt be a CEL at all. I have an x pipe w/ 2 high flow cats.....never got a CEL
this should be tech

 

[CobraRed_96_GT]

after a few bad words due to the passenger side where the pipe connects to the manifolds, one of those bolts is a major PITA

i heare ya, i had to use a 1/4" drive and extension with a 180 swivel before the socket cuz the bolt is so small. Thought i was going to break the extension from torqueing it.

 

[Dragstr05]

^^^yep

when you got on it the a/f must have dipped into a range that the rear o2 sensors liked seeing, so the ecu got happy thinking you put your cats back and took the code away.

Though it has no effect on performance, the rear o2's job is to make sure the cats are working properly, and is merely a OBDII Emissions related component, not a sensor that can affect fuel/ignition parameters.

While the rear O2's dont directly control the fuel trims, they can/will affect performance. I was told that running with no MIL's throws the computer into fail safe mode. This info came from a senior master ford tech, who also has a drag mustang. I can speak for this as well, cause as soon as I put my MIL's in, the car deffinately pulls a little harder, especially at higher speeds.

If the CEL went off, dont worry about it. Going WOT will not just all of a sudden turn the CEL off either just because of a richer A/F ratio. WOT is not a drive cycle.

 

[mustangcam]

what do you do when the ses light is on? do i take it to the dealer to see what the code is? cuz mine came on after the o/r x-pipe went on and i actually used the mils.

 

[d98gt]

Autozone pulls codes for free

btw-the light returned