Hey Guys,

This morning I was running down to visit my parents. I was cruising around 75, got a break and easily went up to 90, the engine misfired and the restricted performance light came on.

I eased across 3 lanes of traffic and went down the freeway offramp. When I got down to about 20mpg the check engine light and restricted performance went off and the car seemed normal.

I got off the freeway and shut the car off for 30 seconds. I started it back up and everything seemed normal. I drove 25 miles at 75 with no issue.

I finished my visit with my folks and drove 50 miles home at a max of 75. And the car ran without any issue.

I got home and plugged in my code reader.

Following codes came up:
P0300
P0305
P0307
P1313
P1111

I drove my wife to dinner tonight and no issues.

The car has 110k miles. I keep her well maintained. My mechanic is a great guy, but he doesn't want to fix anything that ain't broke. He had the car a couple of weeks ago to replace the fuel pressure regulator. I asked him to check for any preventative maintenance and he said not to worry for another 10k miles.

With theses codes, is it just a fluke, or should I be pre-emptive and order some coils and plugs? And is the 1313 code just a result of the mis-fire or is that another possible issue?

Thanks in advance for sharing your knowledge and experience.

Dave B


PS - If there is anyone in So Cal who has fixed the head rest issue, and would like to be hired to fix both of mine please let me know

 

First check for air leak via fuel trims as it may not be the parts you list.

 

My 05 STR did the exact same thing yesterday I have not had it to my mechanic yet to have him scan it because I am leaving town for a week. I am very curious to know what you found out I was on freeway on ramp accelerating hard and got the exact issue you described.

 

Update: It's been 3 weeks. I was gone on my honeymoon for 1 week, but since the incident there has been no further incidents with the car.

I don't know if I should be checking the codes regularly or I don't have to worry about the codes until something is unusual.

I will say that I bought a lilltle Handheld OBDii With all the codes off of Amazon for $24. Fits in a shirt pocket, gives the codes and what the codes mean. Nice little pocket device.

Dave B

 

I found - the hard way - that misfire codes can be caused by contamination or by waterlogged spark plug cavities.

I understand that CA does not get as rainy as the East Coast, but maybe you OD'd on the car wash? The covers over the coil packs are not really watertight.

Still, I'd get a few spare coil packs. Welsh has a good deal; otherwise search the Web.

Keep in mind that:
a.) Sometimes the misfire confuses the ECU and it flags a wrong coil. That is why you may see randomly moving indications.
b.) The cylinder numbering scheme changed about 2001-2003. Google your car year of manufacture. Early models had 1-2-3-4 on passenger side, 5-6-7-8 on driver side. The current ISO spec calls for odd numbers on right, even on left. The display on your OBD reader may point you to a wrong location.

Here is an example: I had an oil change done by my trusty foreign toy mechanic. The idle was misfiring when I picked up the car. I suspected that they spilled some oil and ran cleaner over the covers. The codes showed #3 and #6.
I did it one up: lots of Gunk degreaser and water. At first, the car ran fine, but the next day it complained about #6 and #8. When I pulled out the coil packs, the cavity for #8 plug was filled with a mix of water and detergent. I swapped #7 and #8 (probably the only one that mattered) for an aftermarket coil pack from my stash and did a 500+ mile run to Washington DC this weekend in torrential rain. No problem anymore.

 

I'm tracing a similar issue down myself and have done a few searches on here. It seems to be coilpack related, and likely contamination. Mine look dirty but are making good contact, but last weekend I hosed them and the connectors out with the electrical cleaner from AutoZone. It's improved, but not totally gone yet. Learning about how the covers over them aren't really watertight was annoying, but likely the cause. A bit more fine-tuning to do...

 

For what's worth, I usually put a bit of dielectric grease into the coilpack rubber "tube" and smear some on the outside of it. It should reduce the chances of water getting in.

Also, I "moisted" the perimeter gasket of the coilpack cover with dielectric grease. It probably will attract dust, but should fight off some water.

 

Another thread I read on here recommended the same. I suppose it can't hurt! I may try the same, but I think I've got a bad coil pack now, after codes are reading for Cyl. 1 now after I first saw the code on Cyl. 2 and swapped them... ahhh HA! Hopefully.