I posted in another thread about a p0201 and p0301 code and tried everything suggested there. It ran well for a while but started having problems last week while on a trip out of town. After driving for a few hours it started to die when we came to a stop a couple times and then had trouble getting going before it kicked in and ran fine. Got it home and had it in the shop for a week and they couldn't get the engine to replicate the issue so they couldn't diagnosis it. I drove it this morning and it started running lean like it was only running on 4 cylinders. I'm not getting the 301 code any more, but I am still getting the 201.

I've noticed that the dash board says service traction stability system (or something like that) as soon as the engine starts to run rough. At this point I'm wondering if I have a bad ground wire, a bad catalytic converter, or something different. I've read some forums that mention PCM and others that say the Throttle Body cleaned. I'm going to look at the ground connection which I was told would be on the wheel well, hopefully I can find it. Also going to run fuel injector cleaner and clean the throttle body. Any other suggestions or thoughts??? At this point I'm about out of ideas and may have to take it to a dealership to see what they can find... I hate this idea because I'm afraid of throwing more money at random guesses.

 

#1 fuel injector. Remove and clean connector, also inspect wiring.


Holy crap, you had this issue a few months ago, and you know the problem is from the #1 fuel injector.
Now you want to rebuild the truck?
Did you clean the contacts on the injector too?
If you want to throw parts at it, replace the #1 injector they are cheap!
I have a new ACDelco set, been sitting in the garage for 7yrs, just in case 1 fails.

What causes the P0201 code?

• Faulty cylinder 1 injector
• Wiring harness that has an open or short
• Poor electrical connection in the harness or connector

 

Lol... I don’t want to throw money at it or rebuild it. I already replaced the #1 injector a couple months ago after replacing the spark plugs. It has 165,000 miles on it so I figured new plugs wouldn’t hurt. It ran fine for about 2-3 months then just started having issues again this week. I don’t want to look at the injector again unless I absolutely have too. That’s an 4-5 hour job just to get to the fuel rail 😭

I’m convinced it’s a wiring issue at this point, but I’m just a weekend hack of a mechanic so I could be wrong. Tonight, I cleaned the throttle body, added a fuel treatment, and cleaned the main grounding connection. It ran smooth on test drive and the codes cleared without me having to clear them. I’m going to drive it a couple days and see what we get.

 

Yes indeed, loss of signal to the pcm. TB and fuel injection cleaning is a good thing, however that will not repair a signal loss. The same ground is going to #2,#3,#4, injectors, why is the issue ONLY with #1? Check the wires/connector again to #1!
Btw, what is the part # of the injector you installed?

 

I don't recall the part number and I can't find the invoice. I usually get the parts from rockauto and usually get AC Delco. I think I got it from Autozone this time because I needed the part that day. I do think I went with a cheaper part. Looks like I need to tear everything a part again and get to the injector. Ugh! What you are saying makes sense. Thanks.

 

Update... After driving for several weeks the issue repeated itself again yesterday. Today I checked all the wires from the coil to the injector and found 3 wires that had the coating worn off, including on the #1 fuel injector connector.


#1 Injector connector.

harness connected to injector wiring harness. Black wire connects and leads to #1 injector

Green wire has a little bit coating missing

I ordered new wiring connector for the #1 injector. I can't tell if the wire is broke on the inside, so I'm going to play it safe and get a new one to splice and solder. Also replacing all the fuel injectors since I have it all disconnected. It is quite a job to get to them. I had to remove battery, fuse box, alternator, and wheel well to get to remove the plastic part of the throttle body). Took a couple hours just to get to the fuel rail to remove the injectors. I don't want to do that again. Hopefully the bad wiring is the issue... I don' t want to have to deal with this anymore.

I'll update after it is all put back together and I have driven it for a few weeks hopefully problem free!!!