SES can't resolve problem

[s_jo4]

well the ses has been on my 01 gtp for about a month now, i can't figure out what the problem is. i've replaced the fuel filter, pvc valve, air filter, egr valve, and spark plugs and still throws up p1404. i have the gm service manuals for that model and it hasn't helped in a diagnosis. it all revolves around the emissions (egr to be specific) states the books. i've looked for loose vacuum lines, checked wire connections at pcm, throttle, etc. and nothing. my fuel economy sucks, instead of 23mpg i'm getting 15, and have added no mods in that time. about a month ago it started surging really bad, not at idle but during slow acceleration. after that i started using fuel injector cleaner, bumped to 93 octane, and replaced various parts previously listed to keep surging to a minmum (almost gone now, but feel it every other day or so it seems). if anybody can help i'ld like to hear what you have to say, otherwise looks like i have to see the dealer.

[GMMerlin]

You didn't post what engine you had.
If it is a 3.1, there is a GM technical bulletin#01-06-04-018A for a calibration update for that code.

[omicron]

Originally Posted by GMMerlin

You didn't post what engine you had.
If it is a 3.1, there is a GM technical bulletin#01-06-04-018A for a calibration update for that code.

He said he had an '01 GTP, and since 1997 GTP has had the 3800 series supercharged.

I would suggest taking it to a dealer before you end up replacing everything you don't need to. See if the fuel pump resistor is the problem too, because it may cause that to happen, along with other things. Just be glad it doesn't stall on you every left turn (like mine did).

[roberts5]

I have a 1999 GP GT. It has the same surging problem you have. I dont know what is causing it. I can lightly touch the brake pedal and it smooths out. Some say its something to do with the lock up converter. Have you fixed yours yet? Any help is appreciated.

Thanks,
Greg

Originally Posted by s_jo4

well the ses has been on my 01 gtp for about a month now, i can't figure out what the problem is. i've replaced the fuel filter, pvc valve, air filter, egr valve, and spark plugs and still throws up p1404. i have the gm service manuals for that model and it hasn't helped in a diagnosis. it all revolves around the emissions (egr to be specific) states the books. i've looked for loose vacuum lines, checked wire connections at pcm, throttle, etc. and nothing. my fuel economy sucks, instead of 23mpg i'm getting 15, and have added no mods in that time. about a month ago it started surging really bad, not at idle but during slow acceleration. after that i started using fuel injector cleaner, bumped to 93 octane, and replaced various parts previously listed to keep surging to a minmum (almost gone now, but feel it every other day or so it seems). if anybody can help i'ld like to hear what you have to say, otherwise looks like i have to see the dealer.

[s_jo4]

yeah, old thread, but i got the problem fixed. surging was related to a broken resivoir on the pump letting it float freely in the tank. also part of the problem that later affected the running state of the car was a short in the fuel pump supply voltage under the hood, that was also fixed and haven't had any problems from that since. the egr problem was a healthy build-up of carbon deposits from the intake clogging one of the pipes so replacing the egr was no help less you did the pedestal too. hope that helps, let me know if you need anything else.