2007

Hey all!

This is my first post here but have been reading other threads for a while now. This site has a ton of info that will help me and others out greatly.

On to this post. 2007 HHR 2.2L, auto, 72500 miles. Getting check engine light and code said misfire #3 cylinder. Which side is #3? Is passenger side of engine #1 or is driver side #1?

Thanks for any info and will post for updates if I can't fix this problem.

whopper

Passenger's side. Just think of the numbering as if the engine was mounted fore/aft as in a rear-wheel drive, with the transmission in the rear.

843de

to the forum!

Were there any other codes set, besides the P0303 misfire code on cyl #3?

There are a few possibilities as to what is causing the misfire, bad plug, loose valve seal, failing injector, cracked head, bad head gasket, and even corrosion present in the fuel rail.

If you have any other info or codes showing, it'll help point you in one direction or another with the diagnostics.

2007

Ok, thanks whopper.

Let me explain my problem more in depth.

In may 2013, I changed the sparks plugs at around 69,000 miles. since then the idle seemed to be a little rough. Not that the rpm's would rise or lower, just seemed to feel rough at idle. No check engine light yet. Fast forward to last Saturday 8-3-2013, 1/2 mile from work, sitting at traffic light waiting. Light turns green and go on as normal(not fast at all, 2800 rpm shift) and at 1-2 shift transmission felt it had a shift kit in it and BAAM, engine check light comes on. So on Monday at work I had a buddy check to code and it said #3 cylinder misfire. Ok, just changed plugs in May, so maybe coil is bad. Bought new coil, installed it Wednesday night and today in the morning had the same co-worker check the code again. This time is said p0303 #3 cylinder misfire and P1516 - Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance.

I have no clue what p1516 is so we cleared the codes today and then at lunch the check engine light came on again. So we checked it again and only p0303 #3 cylinder misfire was shown.

That is my problem. Do you think a spark plug is bad? Or is something else with that p1516 code a problem.

Thanks and sorry for long post.

2007

Thanks 843de, I was typing my previous post when you did. I'm thinking maybe bad plug. And I have no leaks coming from engine compartment (as in oil/coolant). Nothing on concrete driveway.

843de

Well a P1516 code can be one of the following conditions....

- Faulty Throttle Actuator Control (TAC) module
- Throttle Actuator Control (TAC) module harness is open or shorted
- Throttle Actuator Control (TAC) module circuit poor electrical connection
- Check Throttle Actuator Control (TAC) module connector for water
- Binding or bent throttle plate-failed throttle body

It may have been spurious, but keep an eye out for it.

What type of plugs did you install, these engines are notorious for throwing codes unless the proper Delco Iridium 41-103 plugs ars used.

whopper

x2!!!!

2007

Ya, I'm pretty sure I did not use Delco Iridium 41-103 plugs. So the first thing I should do is buy new plugs then?

donbrew

If you changed the gap of the plugs out of the box, that is the problem. The same type of thing happened to me last week, ran fine for 3,000 miles then CEL. The electrode on the new plugs cannot deal with being touched, they are gapped at the factory, you just have to learn to trust them.

If I follow correctly, you went out and bought a new coil without even checking the plugs? And after you replaced the coil #3 you still have a p0303? Either the plug or something in the cylinder is bad.

The p1516 is probably just a flukey, you will probably eventually get a p0300 also.

jay loukakis

Right after I bought my HHR I changed to the E-3 plugs ran rough had it scanned 20,000 misfires changed to the AC-Delcos 40,000 miles no more misfires.