if i reset my computer at 10000 ft and drive it down to 5000 would that be ok to lean it out. i'm having a problem with hydrocarbons in smog testing running slightly rich. this is on a series 5 '90 gxl

 

It will quite possibly do nothing at all. You have other problems.

 

is there anything you could suggest i've recently had it tuned it got better but was still bad appx 1200 limit at 400 new egr valve maybe

 

oh i had the same problem what i did to pass was to drive my tank to a little less than half a tank full of gas and went to the hardware store and bought de-natured alochol. I pored in half gallon into the tank. De-natured alcohol makes your engine burn hotter and cleaner, you should be able to pass then, and i also did a oil change before going in and also replacing the spark plugs. try that hope it helps

 

either that or the ACV was/is bad. Did you fail idle or load?

 

failed both

 

That sounds like a catylist issue..

 

cool thanks i'll try a new one and see

 

Maybe not a catalytic problem!!! I'm haveing the same problem, with it runnin' to rich!!! I put on a new cat and it didn't do a thing!!! however in my case a new TPS helped a little although not completely!!!!




Some thiongs for u to check that might cause it: MAF(could be stuck open), air temp sensor, coolant temp sensor, BAC, fast idle cam(most likely not a problem on yours) thermo wax plunger, injectors cleaned, ACV, or the dreaded vaccum leak!!!!!



Doesn't cost any more than a trip to the FSM or haynes to check these things!!! Might help, might not, either way never hurts to get a little peace of mind!!!!!


Apex

 

See if your OMP is sticking Open.you could be injecting Oil into your Housings and Getting a High HC reading from that...a new catalytic is Wise when it comes to an Etest,along with a Good tune up.Drive the Car HARD before you take it in(like twenty minutes Highway,high revs)..that will have the cataytic hot,so it will be Doing it's job of Sucking up the Bad **** in your Exhaust..It is also good to See if you can direct the Output of your air pump,To go to the Cat.Via the Split air pipe.That will give you Fresh air in With the Exhaust,and Dillute your Exhaust gases,and therefore give you a Lower Emission reading..TIP:look up J-Rat's Recipe also..that works too!..suprised he never mentioned "the trick"!..anyhow now you have some things you can Look into.

 

No. The stock ECU relies on an atmospheric pressure sensor, located in the passenger side kick panel, to make map corrections based on altitude. There would be absolutely no change.

 

Isn't the ATP on a SERIES FIVE located internal to the ECU? Yes. Unlike a Series four car.

It does sound like a catalytic converter, at bit anyway.

If you check out your ACV and it is working like it should, AT THE RIGHT TIMES, then I'd buy a catalytic converter and pass inspection.

We're all ***-U-MING the airpump and ACV is installed.

 

wouldn't do a thing.. FC's have barametric calibration.

And in the FAQ for FC sticky thread, it outlines what to check based on what fails for emissions