P0204 P0304 DCT's

[Jasonholcomb]

I could use some help. I have a 2010 FFH with 119,000 miles. It has been a great car. I've had all maintenance done through the dealer up to this point.

 

Earlier this week there was a sudden loss of power with rough ride and CEL came on. I checked the DCT's and got P0204 and P0304. I changed all 4 plugs and coils and the car ran great for 1.5 days (about 100 miles). Got the same codes (same cylinder misfire with cylinder injector circuit open). Rides rough with no power. I suspect it could be the wiring to cylinder 4 since every other cylinder seems okay.

 

Does anyone have experience diagnosing this problem and possibly repairing/replacing the coil wiring harness?

 

Any thoughts would be appreciated.

 

Jason

[lolder]

It sounds like a fuel injector or wiring is bad and it's misfiring on one cylinder take it to the dealer or appropriately skilled mechanic. I did have rats chew through the injector harness of a 2004 V6 Avalon a few years ago and kill one cylinder. It was an expensive repair as the mechanic had to remove the manifold to get at the harness of the rear cylinder. He was able to get a pigtail connector for the injector and splice it where the wiring had been chewed through.

I think this should be a straightforward repair.

Edited August 30, 2014 by lolder

[acdii]

Yep, it is teh injector causing the misfire. If you just get the 030x code, that would be one of 3 things, coil, plug or intake leak, but two codes together, misfire and injector, that would be the injector or related wiring.

[Jasonholcomb]

Thanks for the replies. Here's an update.

 

I was a little unsure how to proceed with diagnostics so I took it to a trusted mechanic. He reported the pressures on fuel injector 4 were lower than the other 3 and that the injector 4 pressures got lower as the engine warmed up. He replaced the cylinder 4 injector and my car has been running fine for about 150 miles.

 

Here's a cost summary:

 

Tune up was about $325 ($75 per coil and $7 per spark plug)

Mechanic diagnostics and repair $240 (the fuel injector was only $52)

 

I guess my advice to anyone who encounters this problem is to first do the tune up (coils and plugs) especially if the car has more than 100,000 miles. If the problem persists and there is no apparent damage to the wiring harness then the fuel injector is relatively cheap and sits on top of the engine in a rather accessible position so should be a reasonable DIY fix.

 

Thanks again for the replies. Without visible wiring damage I was not comfortable fooling with the wiring harness.

 

Acdii, if I had gotten your response before I took it to the mechanic I probably would have just gone with the injector and replaced it myself.