No parts required to check the wiring harness, it’s the most logical source of your problem, especially since you have confirmed it ran fine for three months.

 

The only reason I am suggesting the throttle body is because one of the items on my list is the throttle positioning sensor and it's not a separate piece. It's attached to the top of the throttle body. Unless I'm missing something.

I am going to try to take it apart Saturday morning and inspect those wires. I can also check the continuity with my MM like you suggested.

We can't go to the junkyard till Sunday morning so hopefully I'll find it in the wires before then.

Thanks,
Jessica

 

That’s good, to bad the borders still closed, I could help you out, maybe swap harnesses with my HHR , see if your misfire transfers to my engine!

 

I seriously doubt that the TB is going to cause a miss fire in just a specific cylinder (#1). The TB is just an air inlet/ metering valve for the entire intake manifold. All 4 cylinders get equal input from the TB and attached sensors.
Not seeing the reasoning to suspect it would mess up just 1 cylinder.
Hope this isn't a "I read it on the Internet" thing.

 

Ok deep breath... And please don't mind my sarcasm...

Again it's not the actual throttle body that I want to replace. This is where I found the list - https://repairpal.com/obd-ii-code-p0301. Yes I found it on the internet. LOL Isn't this the internet? LOL I want to replace the throttle positioning sensor but this post - https://www.chevyhhr.net/forums/prob...-sensor-49308/ - says that it is integral to the throttle body. So to change one I must change the entire piece. Again I read this all on the internet. I can't find anything on this in my encyclopedia Britannica but that could be because it's the 1982 edition. I'm joking!! But yes everything I have tried I read on the internet. And most of it came from this forum - again on the internet. LOL If you are reading my post, guess what, you read it on the internet. LOL

I understand how the throttle body works. I had issues with it being dirty years ago and replaced it with one from the junkyard. Granted it may not be the issue at all but for $30 I'll eliminate it from the equation.

I found another post on this forum that the person changed the VVT solenoids and his code and issues went away. Another person on that post said they remove those and clean them during every oil change. What is in the engine came with the engine. The auction site that sold the car to wherever I bought the engine from says the cars primary damage was Biological/Chemical and the secondary damage was Hail. Here is where I found that - https://www.autobidmaster.com/en/car...TLE_DENVER_CO/
So who really knows what happened to it but I'm trying to take the whole picture into consideration.

I will update this weekend after I inspect and test the wires, before I go to the junkyard.

Thanks,
Jessica

 

We are on the Internet!

 

I was able to inspect the wires today and they all look fine. Nothing is broke or frayed or pulled. I didn't get to check the continuity yet. My meter is MIA so I am going to have to tear the garage apart to find it or see if I can borrow one from work.

We did go to the junkyard and I got the parts I wanted plus some. LOL And of course while writing this just thought of something I didn't think of while there. The struts for my gate. LOL Maybe next time.

I'll update probably Tuesday.

Thanks,
Jessica

 

I hope you find your multimeter, the wires may appear to be good but, underneath the insulation, could lurk the problem.
We’ll wait.

 

I found my multimeter!! Finally! I haven't done anything this week. LOL They had inventory at Walmart this week so my cousin had to work overtime. And I've been taking my mom home everyday after work so by the time I get home I just want to relax. LOL This weekend though I will get back to testing the continuity and I will post my results. Maybe I can fix my door this weekend too. It'll be nice to take the tape off of it and not hear the wind while driving. LOL

Thanks,
Jessica

 

When we went to the junkyard last weekend we grabbed a wire harness for the fuel injectors. I have tested it for continuity and it is good. We are going to swap it out tonight. I honestly don't think it's going to make a difference. The VVT Sensors/Solenoids that we grabbed were from an HHR engine, not a Cobalt and they aren't the same as what's currently in the engine so we didn't use them. I didn't pay for them so not concerned. We did replace the throttle body and no it didn't make a difference but at least it's checked off my list.

I tried to open a warranty claim with the place I bought the engine but they are telling me that I ordered and they sent the correct engine. So even if there is an air/fuel ratio issue they don't care and don't seem like they want to help me. Just my luck.

I am going to try to talk to the shop that installed it this weekend and see what they say or if they can help me with the warranty. I can't find any information anywhere that says the two engines can't be interchanged or what issues could occur if they can't be.

Thanks,
Jessica