mattr178

All I did was replace the spark plugs and spark plug wires. I changed the wires out with MSD and the plugs with NGKs. Now car will start and idle where it's supposed to (600-700 rpms) then start to sputter for about 2-5 seconds, eventually dying. I have recently replaced fuel filter, but that was a week or two ago and it was running fine until I changed the plugs. I checked the DTC and only thing that popped up was a H code p1514, and I only think it did that because, I was looking at the forums for possible answers, and one suggested was to unplug the maf and then try it, so I did, and when I started it barely started, said reduced engine power. SO I figured that was gonna help and plugged it back in. I installed a vararam intake a couple weeks ago, and again it has ran fine up until after finishing the spark plugs job. Any suggestions... I plan on checking fuel pressure tomorrow if I get the chance. But anyone else have a similar problem ever? Thank you.

mattr178

Ttt for the morning. Posted late last night.

mattr178

Fuel pressure is right where it should be at... could my throttle body be done for or the throttle position sensor?

SaberD

unplug the maf again and check for corrosion in the connector. clean it up and reinstall.

You will get the reduced engine power message if the pcm isn't communicating with the maf.

Cutlassmaster

Which plugs did you install, what is the gap and did you ensure the wires are push all the way on the plugs and coils? From what you said, no issues prior to plugs and wires. That is what I would be looking at first.
Chris

mattr178

Installed NGK laser iridium. I am pretty sure all the plug wires are all the way on. I checked more then once but I suppose it won't hurt to check again. I will also check the maf connections.

MG RED 99

Could have gotten a crappy MSD wire. I've heard mixed opinions on them not being that great. Try putting your old wires back on and make sure they are seated properly. If that doesn't work then put your old plugs back in and see what happens. Always start from the point of failure. If it worked prior to the plugs and wires then that's your problem, don't go chasing other areas until you've ruled them out. If the wires are your problem a lot of people use the GM performance wires.

I personally had a problem with 2 bad msd wires and wasn't even aware of it until my tuner did a check while doing other tuning work on the dyno.

Also check to make sure you have the proper plug gap.

mattr178

So even though it starts right up it could still be the plugs and/or wires?

GoatKart

Simple check...

Put your stockers back on, if problem goes away... you have bad wires...

If problem persists, your stockers could be broken from the removal (yanking on wire instead of boot), your install faulty (not fully on the plug), or you have some other problem lol