Installed Offroad pipe last week, my gas mileage is horrible now

derek02gt · #1 (**permalink**) 06-12-04, 10:14 PM

i dont know why but my gas has gone to crap..and i blame it on the offroad pipe but im not 100% sure so please correct me, i used to get like 255-275miles on a full tank..thats combined city/highway..now im only getting 200-210..a HUGE DROP in gas mileage..can anybody tell me why?i have installed my mil eliminators and there is a SES light still on..but this is frustrating..30 dollars of gas gives me 200 miles..please let me know whats going on...btw if i unplug the front 02 sensors..would that help?thanks

wht99gtconv · #2 (**permalink**) 06-12-04, 10:57 PM

Did you disconnect the battery for about 5 minutes, if not do that and that should take care of the SES light. For the gas problem only thing I can think of is you might need to change your 02 sensors.

**triggz** · #3 (**permalink**) 06-12-04, 11:30 PM

If the SES light is still on, your MIL elims are faulty. The light should go off by itself soon after being patched.
I suggesting returning them and patch the O2 sensors yourself, its cheap and easy once the sensors are off. No cats will NOT hurt your gas mileage. It improved mine a bit. I just got 23.6mpg on a late nite 150mile trip home.

Heres a wiring diagram..you can get the parts at Radio Shack for under $5.

wht99gtconv · #4 (**permalink**) 06-12-04, 11:40 PM

Sorry to disagree, but anytime the SES light comes on it has to be reset.

**triggz** · #5 (**permalink**) 06-12-04, 11:43 PM

We'll have to agree to disagree then. My trouble codes and SES light went away by itself after being patched within 10 miles just as suddenly as it originally came on.

wht99gtconv · #6 (**permalink**) 06-12-04, 11:46 PM

How long was that ago

NV01GT · #7 (**permalink**) 06-13-04, 12:49 AM

It might be the LEAD FOOT syndrome.

**triggz** · #8 (**permalink**) 06-13-04, 01:01 AM

Quote:

Originally Posted by wht99gtconv

How long was that ago

My patchwork? About 3 months ago...

derek02gt · #9 (**permalink**) 06-13-04, 02:10 AM

sorry guys but I am truly a idiot, i meant "havent" instead of "have..I haven't installed my mil eliminators just yet..could that be a reason?is it possible to have bad o2's on a 2002 car?

**COramprat** · #10 (**permalink**) 06-13-04, 03:10 AM

Quote:

Originally Posted by derek02gt

sorry guys but I am truly a idiot, i meant "havent" instead of "have..I haven't installed my mil eliminators just yet..could that be a reason?is it possible to have bad o2's on a 2002 car?

That is your problem...that is what the MIL's do...fools the computer into thinking you have cats.

**46gtsblown** · #11 (**permalink**) 06-13-04, 07:07 AM

True it fools the computer.
However, IF the MIL is triggered by not having cats or faulty REAR O2 sensors it will make ZERO difference to the running of the car.
The rear O2's are there purely to monitor the cat function.
The EEC will not pull timing or go into limp mode just for that.
Do not disconect the front O2 sensors this will screw things up big time.
Make sure that you have installed the O2 sensors correctly and they are hooked up.
Make sure you have no leaks
Reset the computer.
Clean your MAF ( I do this as a first step for any engine trouble shooting)
If is has been a while run some injector cleaner through it.

Dwayne

03poontanggt · #12 (**permalink**) 06-13-04, 11:03 AM

How do you like the smell. I have the same problem with gas. I ran the hell out of it before the X and I run the hell out of it now. 255-275 before 190-210 now