[cwwozniak]

My 2007 Dodge Caliber with a 2.0 L 4 cylinder engine and automatic transmission started having a problem a couple of days ago. It will shudder and have little power when accelerating from a stop or from a very low speed and runs fine once up to a bit of speed (> 30 MPH) Acceleration at higher speeds is not a problem. The problem only seems to appear in hot (90 degree +) weather or after driving a while in slightly cooler temperatures. The check engine light will either come on and stay on after the shuddering or will come on and go out. I had an auto parts store check the OBD computer and it came back with a P0301 code, "Misfire in #1 Cylinder". From what I have read on line at other sites, possible causes of a P0301 code are:

Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer

Just wondering if anyone here could suggest what order I should check things out and what I can eliminate as a possible causes, based on my particular symptoms.

[Drabdr]

Just some thoughts ...

I would think the code printout would be in order of priority.

Do you think it could be bad gas?

I'm not a big fan of "cleaners", but it might be worthwhile in this case.

I would start with new spark plugs and wires (easiest and least expensive), then have the code reset.

[cwwozniak]

Thank you for the suggestions.

My last few fill-ups were at the same gas station. The tank was nearly empty and I did a fill-up with a different brand of gas this morning. I didn't notice any change for the rest (20 miles) of the drive to work.

I'll pick up a bottle fuel injector cleaner gas additive on my way home tonight.

I'll take a look at what it takes to get to all 4 spark plugs on my engine.

[Drabdr]

Originally Posted by cwwozniak

Thank you for the suggestions.

My last few fill-ups were at the same gas station. The tank was nearly empty and I did a fill-up with a different brand of gas this morning. I didn't notice any change for the rest (20 miles) of the drive to work.

I'll pick up a bottle fuel injector cleaner gas additive on my way home tonight.

I'll take a look at what it takes to get to all 4 spark plugs on my engine.

It may be time for new spark plugs anyway. Check the physical condition of the wires. If they feel hard or appear brittle, I would replace them also.

If you want, you may see about what it would cost to have them clean out the fuel injector. I know some people are really sensitive about running cleaners through their system. But the additive cleaner is quick, easy, and cost effective.

[koldbloodkev]

This would be my order of operations (cheapest and easiest first)!
1Faulty spark plug or wire
2Faulty oxygen sensor(s)
3Faulty fuel injector
4Faulty catalytic converter(s)
5Burned exhaust valve
6Defective computer
If it's #5 you will have poor compression,
If it's #4 it would be a constant lag on the engine
If it was a faulty coil you would most likely have two cylinders not firing.
Poor compression
Faulty coil (pack)
Running out of fuel

[koldbloodkev]

You may also try a self diag. on it and see what it says. Turn the key to the on off on off on, (not to start) and watch the check engine light it will blink in a series of two digit numbers eg; 5 blinks pause 3 blinks is a code 53 count them all until it gives you a 55 (end of sequence) and see what that refers to at www.moparforums.com or www.moparts.com
Good luck.

[Drabdr]

Originally Posted by koldbloodkev

This would be my order of operations (cheapest and easiest first)!
1Faulty spark plug or wire
2Faulty oxygen sensor(s)
3Faulty fuel injector
4Faulty catalytic converter(s)
5Burned exhaust valve
6Defective computer
If it's #5 you will have poor compression,
If it's #4 it would be a constant lag on the engine
If it was a faulty coil you would most likely have two cylinders not firing.
Poor compression
Faulty coil (pack)
Running out of fuel

Originally Posted by koldbloodkev

You may also try a self diag. on it and see what it says. Turn the key to the on off on off on, (not to start) and watch the check engine light it will blink in a series of two digit numbers eg; 5 blinks pause 3 blinks is a code 53 count them all until it gives you a 55 (end of sequence) and see what that refers to at www.moparforums.com or www.moparts.com
Good luck.

good responses.

[cwwozniak]

Thank you for the suggestions. I just started my second tank full of gas using Textron fuel injector cleaner. The check engine light did not come when I started on the first tank full in cooler weather. It has not come on since.

[daniel_b2380]

Chuck,
you might also check your radiator,
the newer style anti-freeze used in the last few years will get "gummy" if it is allowed to mix with air,
OR
it gets some of the older style stuff added to it
which would prevent the coolant temperature from being properly lowered,
in turn, altering and causing performance issues
especially with the ambient air temperatures being what they have been over a good portion of the country during this heat wave

you can read about all the technical stuff:
anti-freeze gummy
http://www.google.com/search?hl=en&s...ze+gummy&gbv=1

[dustyjay]

I have experienced this same problem on my 98 Navigator, Turned out it was the Coil Packs. Code Scanner called up the P0301 code everytime. Pulling power over 35MPH was no problem Miss would happen at about the same speed everytime. So if the problem arises again I would suggest checking into the Coil Packs. For me it turned out I had to replace all 8 coil packs to correct the problem Even though it was supposedly a miss in the #1 Cylendar.

[cwwozniak]

The problem did show up again (same symptoms but did not do a new OBD scan). This was after going through two tanks of gasoline with injector cleaner and a different brand of gas. I think it may be related to both temperature and humidity where the higher the humidity, the lower the temperature has to be to trigger the problem. I am suspecting a Coil Pack problem as well. I read on another board that moving all of the wiring between two Coil Packs should isolate the problem to Coil Packs if the misfire OBD code follows the swap.

[dustyjay]

The thing is if you do isolate it down to the Coil Pack, you would want to replace all the coil packs at the same time. For me that would have been almost $1000 using factory parts, but I got smart and went to O'reilly Auto Parts and replace all 8 with Accel Coil Packs for $30 each. I would look into that option rather than a dealer parts.

[dustyjay]

Also, I would swap the coil pack itself between cylendars instead of the wiring. swapping the wiring will cause the timing to change so that for example if you swap the wiring between #1 and # 2 the number #2 coil will fire when the number one coil should be firing.