Old Member, first post: P0303

[Aizen Sosuke]

Hi all. I've been lurking this site for over 6 years since I bought my 08 CX-7 in 2010. Thanks to many posts in here I got the AC compressor and VVT done under warranty at around 60k miles. I have maintained this baby since I got it with only 20k miles with synthetic and she's given me zero issues. It's my daily, I have a 370Z but that barely gets driven this days.

Anyways for the past 2 months I have been getting the CEL with P0303, cylinder 3 misfire. I replaced the spark plugs since the originals have nearly 90k miles now anyways and I went with another set of NGK laser iridium with a .028 gap. These are the same as the original Fomoco just rebranded. I also switched the coilpack to cylinder 4 and reset the code. Two days later it came back during a cold start in the morning. It's the same code, same cylinder. I think we can safely rule out spark. I will be taking it to the dealer since I do not have the proper scan tools to determine what is wrong. Car is bone stock and it is actually running quite well. I do not feel any misfire whatsoever. I've searched the boards and everything from bad injector seals, injectors themselves, PCM, HPFP, purge valve and many more have been the cause of these. I'll keep everyone posted of any progress and appreciate any input you may have.

[blackms3_71]

Either dirty valves, dirty injector, or injector seals.

Or possibly dirty egr.

[Aizen Sosuke]

Dealer says compression test is good but EGR was very dirty. They cleaned valve and code came back. HPFP also checks out ok so injector on cylinder 3 appears to be culprit. They quoted me $750 to replace that injector. It will be done by Monday and hopefully that's the end of this issue. I'll report back in then.

[MS3Shadow]

Injectors aren't that expensive, someone that it would cost around $100-175 for each one.

sent from my Nexus 6P

[Aizen Sosuke]

Your price is accurate. I am paying them $220 on parts which includes injector, seals, o-rings and intake manifold gasket plus another $480 in labor. They are also doing a $50 injection cleaning that was due since my 80k service. I'm sure they have a slight mark up on parts but overall I did not see anything outrageous.

[Aizen Sosuke]

Picked up the car yesterday and so far so good. It is running smoothly and pulling hard with no CEL. Dealer also cleaned the valves as they had a lot of carbon build up. I'll post back if the issue resurfaces.