" You probably have a problem"
I think you jinxed me donbrew , just kidding. It has been about 3 days since the Injectors were replaced and today the infamous P0304 code showed up. The car has run very smooth without any symptoms of a problem. No, I am not losing any coolant. Tomorrow I'll see if I can borrow a compression tester and I'll check out the plugs. When should I use the Techron flush and or the Sea Foam flush ?

 

I had a similar misfire with both CEL codes. Both p1174 fuel trim balance and p0300 random misfire. I have an 07 lt 2.4 with 60k. I bought it used with 30k so I have done some work. seems like everything sensor wise on the engine goes bad. so I have replaced timing chain tensioner coil packs and plugs and fuel injectors. that's what immediately fixed my CEL. easy fix took less than 1hr for me. I got my fuel injectors ac delco brand from amazon for 27 each part number 217-2907. id also recommend getting the new seals especially the gray plastic boots. mine were cracked.



I think what happens is that the clogged injectors causes the lean condition which in turn causes the exhaust valves to burn, which causes a loss of compression, which finally causes a misfire in the affected cylinder.

that's imho

hope it helps

 

I have been driving it around a few days and today P0304 and Traction control light came back on. I did a compression test myself from memory and came up with : #1 - 160, #2 - 135, #3 - 150, and #4 - 135. I put a shot of oil in #4 and got a 160 reading. I put it back together and once again it runs very smooth. Hope I did the test right.

 

Run Seafoam through it, maybe the rings are carboned up

 

Funny story. My "problem" went from 'unsolvable' to 'silly me'

I've been getting random CELs which often triggers the Traction control and hard shifting. The codes I get are P0304 and occasionally P0107. I have looked at possible problems which included dirt in the fuel rail. I even did a compression test, which didn't really find a problem. at one point I did find The Crankcase Ventilation hose [12599243] was old and cracked. I replaced it with an generic hose and the problem went away. But then it came back even worse. Which is when I did the compression test.

While doing the compression test, I found the REAL problem. The Outlet Duct [25937095] is torn open where it connects to the CV hose. I duct taped it to check before ordering a new one and the codes haven't returned. Now I just have to find one for less than $80.

 

That is called"unmetered air", too much air, or more air than the MAF is telling the computer.

 

Thanks - it's the reason for the codes. It's also unfiltered - meaning dirty air into the intake. Can't be good for the engine.

 

Another thing I tried was to remove and clean the fuel rail, clean the injectors manually and I replace the orings and cups. I had been getting P0304 so I wanted to test something. As such I swapped 3 and 4 injectors and reassembled it. Today I got a P0303 so it's a bad injector. Can I buy just one "old stock" part or do I need a full set? I don't want to have the the ECM programmed if possible. BTW, what is the original part # for a 2006 2.4l?

 

Yes, you can buy one at a time. Get the part number off of the installed injector. The computer is programmed to the part number.

There is a TSB on the subject for 2006-2007 2.4L. It may have been done on yours, so part numbers may be different. A TSB is not a recall. You can GoOgle the tsb number and get a full copy.

TSB #08-06-04-001B in part: