Issues AFTER spark plug replacement. NEED HELP!!!!

You need to check your fuel pressure. The fuel pumps don't last forever.

A cold engine in warm up mode will run in enrichment mode. That means its requiring 150% more fuel then when its up to temp and switches to closed loop.

The fact that you got a too lean code and it cuts out until it warms up too me means your O2 sensor is operating properly. Look at fuel delivery. If it would be just one injector you'd most likely get a misfire code for a certain cylinder or the random misfire code 300.
 
You might look at the TPS (Throttle Position Sensor). I had the same issue and bought mine at AdvanceAutoParts. It went bad after a year and they replaced it for free under the lifetime warranty. Just make sure they enter it under your name and phone number when you buy it for the warranty to be honored. Not sure what any of this would have to do with changing the plugs but the symptoms sound like the TPS. (Easy replacement/repair) After so many miles, it would be good to change it for preventative maintenance.
 
If no misfire before plug change but misfire now, it's pretty safe to assume it's related to the plug change.

1.) As Durk said, check the wire routing. Even though they're cut to length, it's still very common that people route them incorrectly. The difference is always 3. Cylinder 1-4, Cylinder 3-6 and Cylinder 5-2.
2.) As also mentioned, a lot of times people forget to reconnect the ground wire on the passenger side of the manifold.
3.) The coils should feel like they "pressed" on the plugs. But they do tend to feel a little loose. The reason the old ones felt tight is because the rubber boots tend to stick to the plugs after a while. Eventually they'll do the same with the new plugs.

Don't go throwing parts at it. While a bad MAF, TPS, injector, etc all could be possible causes, retrace your steps first.
 
No one has mentioned it yet, but did you use generous amounts of dielectric grease on the wires and plugs? My truck won't run for crap if I don't use it
 
I did use dielectric grease but only a light coating. I tested everything again today, all the wires are hooked up properly. I installed the new boots under the coil packs, which fit much better but did not fix it. I tried a new TPS sensor and nothing happened. I think it is a fuel issue and it is either a coincidence that its now happening or the plugs are just burning more fuel causing it to lean out.

I am still only getting the P0171 code.

I put fuel system cleaner in it today with higher quality gas. Tomorrow I will check the fuel pressure and re-attempt to check for vacuum leaks, and clean the MAF.

Thanks for all the help guys!
 
sorry I have not followed up on this. Once I got it running I have been playing catch up at work.

It ended up being completely unrelated to the spark plugs, the MAF was going bad and acting erratically. once that was replaced she has been running great.


Thank you for everyones help it is very much appreciated.
 
sorry I have not followed up on this. Once I got it running I have been playing catch up at work.

It ended up being completely unrelated to the spark plugs, the MAF was going bad and acting erratically. once that was replaced she has been running great.


Thank you for everyones help it is very much appreciated.

...the logical fallacy of post hoc, propter hoc--after that, therefore that.

Glad you got it fixed.
 
I did use dielectric grease but only a light coating. I tested everything again today, all the wires are hooked up properly. I installed the new boots under the coil packs, which fit much better but did not fix it. I tried a new TPS sensor and nothing happened. I think it is a fuel issue and it is either a coincidence that its now happening or the plugs are just burning more fuel causing it to lean out.

I am still only getting the P0171 code.

I put fuel system cleaner in it today with higher quality gas. Tomorrow I will check the fuel pressure and re-attempt to check for vacuum leaks, and clean the MAF.

Thanks for all the help guys!

Good to hear you solved it! I get the P0171 code myself from time to time, particularly if it's hot out and I'm accelerating onto a freeway. I searched it the first time it happened and saw several others reference the MAF. Definitely search the code on the forum next time, you may save yourself some effort! Still haven't cleaned my MAF but it's on my list of things to do!
 
Good to hear you solved it! I get the P0171 code myself from time to time, particularly if it's hot out and I'm accelerating onto a freeway. I searched it the first time it happened and saw several others reference the MAF. Definitely search the code on the forum next time, you may save yourself some effort! Still haven't cleaned my MAF but it's on my list of things to do!
I cleaned my MAF thoroughly, I thought. Sprayed it with the MAF cleaner, waited a few seconds, sprayed again, etc. Then did it a second time a few days later. Emptied the can. Looked clean to me.
Well, apparently it was still filthy. My mechanic used a pipe cleaner. I guess the wire needed to be (gently) scrubbed (gently), not just sprayed. I had read never never touch the MAF wire or else it could be damaged but he knows what he is doing so no damage occurred.
My point? Just because you clean it doesn't mean it is clean.
 
Last edited:
I've tried

I have tried all of the above except replacing plugs. I have installed a new fuel pump, new Oand found no leaks. Switched O2 sensors, reinstalled the cat, new muffler, new MAF, smoked the EVAP system, air cleaner. What am I missing?
 
I have tried all of the above except replacing plugs. I have installed a new fuel pump, new Oand found no leaks. Switched O2 sensors, reinstalled the cat, new muffler, new MAF, smoked the EVAP system, air cleaner. What am I missing?

What is your issue? CEL? Misfiring? Stalling?
 

Members online

Forum statistics

Threads
278,307
Messages
3,554,049
Members
248,016
Latest member
Advally Service

Trending content

Back
Top