: Advice from northstar DR??



silver02ta
05-22-13, 08:47 PM
Ive done many searches and came up with afew different possibilities....I have an 05 V8 and recently changed the plugs and yes I have the oem ac delcos. I am getting a skip when im at idle and if I just slightly press the gas whlile driving it skips really bad....if im at idle and raise the rpms to right at 1k it smoothes out and if im driving and it skips, I can accelerate hard and its fine 98% of the time. I have custom exhaust with O2 sims....so wasn't sure if the plugs were bad due to no cats? I have been told plugs, maf, tb..... so if someone who might have a more accurate analysis I would greatly appreciate it :) I have also checked the bolts on the intake and looked for vacuum leaks.

1BadCadSTS
05-23-13, 12:43 AM
Are your o2 sims plugged into the post cat or pre cat o2s?

silver02ta
05-23-13, 08:02 AM
Post

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Im going to get a tune through madtuners also

EChas3
05-23-13, 08:44 PM
I thought STS N* cats are in the exhaust manifold. Are there still O2 sensors ahead of the cats?

1BadCadSTS
05-23-13, 08:45 PM
Always are. Pre cat o2s determine fuel air mixture based on lean/rich conditions taken from the exhaust gas.

EChas3
05-23-13, 09:48 PM
Mmmm, toasty!

silver02ta
05-23-13, 10:07 PM
Mmmm, toasty! ?????

EChas3
05-23-13, 10:23 PM
Very hot!

Probably most susceptable to miread/failure regardless of specific code thrown.

silver02ta
05-23-13, 10:54 PM
what is most susceptible?

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I took it by autozone and had the codes read....maf sensor....map sensor and misfire in cylinder 6...great

Midnight
05-24-13, 03:36 PM
My 05 1SG was throwing a MAF sensor code, and I actually bought another sensor and it was still throwing the code. It turned out that the wires leading to the connector to the sensor had fatigued and broken inside the insulation. One other thing that was interesting is the insulation was kind of sliced in a spiral pattern as if when they wrapped it with whatever kind of tape at the factory, it got cut somehow. I thought it was strange. I cut and spliced the wire back together and no more codes.

I guess my point is you might also want to check for possible intermittent electrical problems (attach OBD2 reader, I have the one from auto-zone I think it was $70, and wiggle wires while watching MAP sensor output), and check the condition of the insulation at that connector if it turns out the sensor seems dead.

scott9001
05-26-13, 06:03 PM
put the cats back on its better for the environment and sounds better... get in with a scanner and see if u only have a miss on cylinder 6 or more could be a coil or one of your sims isent working properly have u checked out your fuel trims?

ddalder
05-26-13, 06:31 PM
I guess my point is you might also want to check for possible intermittent electrical problems (attach OBD2 reader, I have the one from auto-zone I think it was $70, and wiggle wires while watching MAP sensor output), and check the condition of the insulation at that connector if it turns out the sensor seems dead.
This is exactly why code readers are not necessarily a good thing in the hands of people not experienced in troubleshooting. I have repeatedly seen people spend a lot of money throwing parts at a "code" and not the underlying problem that ultimately caused the code to be set. Of course the auto parts stores love this.