Thread: newbe

hi all. just joined the forum. i have some problems with my sisters 1999 grad prix gtp 3.8 that i hope you guys can help.

Originally Posted by slick2500

Nope we dont help people lol
What seems to be the issue?

well. i'm going to look around first to make sure if someone else has had this issue and not sure if i can post in this section... but i will tell you this. its a p0300 misfire code and a hell of a miss that is kicking my butt...did a few things with no luck.

ok guys. i have read the p0300 section with no answers. seems like us p0300 victims have the same problems but yet to hear what it was. this is my problem. my sister has a 1999 3.8 gtp. one day drove car to her sons house, came out and started her car to realize it was missing bad. almost like if you would take a plug wire off at idle. that kind of miss. with the CEL blinking. took it home. was scared. called me i told her to take it to auto zone to check code. it was #5 miss fire. her boyfriend put plugs and wires. still missing bad. i live 30min away so i told her to bring it over. she said that while driving it didn't seem to be missing but at an idle bad miss. i checked it with a code reader. i got p0300 random miss fire. i have a spark checker and checked spark from each coil from one to six one by one and all have spark coming out the coils to the wire and did the same at the plugs with all having spark as well. thought it might be the cat. disconnected at the motor right after the 02 sensor still missing bad. car was getting hot. temp gauge in the car showed normal but on the code reader showed hotter then the car. it got dark so i looked under the car and said theirs my problem. we have the cat,,,-short piece of pipe with the other 02 sensor,,, and then the resonator,,, then a Y back to the mufflers. well, right after the cat at that short piece of pipe with the02 sensor it was glowing. i said OK. took the flange apart at the resonator and STILL missing bad. i didn't think it was the cat because it was glowing after the cat, not before or at the cat only after. at this point i think since the CEL is flashing i think its sending raw fuel down the cat breaking it apart and maybe clogging the resonator. so i left it apart for now. today i checked the fuel injectors wire with a noid light with all having juice to them and removed the injectors just to see if any of them had bad carbon on them which they didn't. then check for fuel to see if they are shooting gas out and all shoot gas out of them. i mean I'm 100% old school. and this new **** is kicking my butt big-time. i haven't replaced any sensors because of my sister not having a lot of money. that's why I'm trying to check as much stuff as i can. i mean, you guys would know a hell of a lot more then i would when it comes to new technology. i mean, would a 02 sensor,-TPS,-MAP sensor,-MAF sensor,-cam ps,-crank ps make the engine run like if its running on five cylinders??? i also checked the fuel pressure switch on. and waited to see if it would drop after like 5 min or more. and held the pressure that is recommended. man. can some one please help me out here.... thank you in advance.

forgot to mention this is my live data..
IMG_20130810_102108.jpgi couldn't show the other two pics

Originally Posted by txslow6

Sounds lien multiple problems. Pull the plugs first and take a look at them. Also with your 16.4 LTFT can be a vac leak. I've also had a PO300 code and it ended up being an injector that wasn't fully seated.

i checked for vac leaks and didn't find any. i had taken the plugs off and only found #5 darker then the rest.
and as for the injectors. made sure they were seated pretty good. still missing bad. whole engine shakes but when i rev engine some seem to almost go away but you can tell the miss is their some yet.

ok, went out today even though i had checked the spark coming out of the coils with my spark tester. i took a pair of pliers installed some rubber hose on the handles and checked each plug wire coming out of the coils and this is what i found. --> yes working--> no not working. take notice how the #1 plug acted.

i forgot to mention that as i was removing each plug wire from the coils the spark would travel to which ever one was next to it and all the coil terminals had spark coming out of them.

what would the LIM be? sorry.

just took the egr off with no carbon clog at all. and both tubes are attached good. thanks tho. i'll take any tips at this point