cggeo555

Hey guys,

I've used the forum quite a bit but first time poster, love what you guys do. I have a problem with my 2007 gx470 that ONLY happens when I am in reverse. It's usually when I first start the car (although that's usually the only time I use reverse). The engine will start missing pretty bad but then it usually stops after maybe 20 seconds and especially if I just go ahead and back out. All the usually suspect dash lights come on and it throws the P0356 error code every time. Sometime this won't happen for several weeks with no problem, but sometimes like right now it does it every time I back up. I replaced the F ignition coil (3rd cylinder from front on passenger side) with a Lexus part from the dealer about 3 months ago but it didn't help. Spark plugs were replaced about 15,000 miles ago but I don't remember this coinciding. Anyone have a clue why this is only happening in reverse? Thanks in advance.

chiph9

Did you check for rodent damage to the wiring?

Chip H.

cggeo555

Yes, the wire has no apparent damage. The wire is pretty short coming off of the ignition coil and then disappears in a very thick heat insulated bundle so I don't think it has been chewed. Thanks for the thought though, that happened to the wiring harness on my old Mercedes. Anyone else have any ideas?

mann777

You replaced the wrong cylinder Ignition coil. You need to chk the No#6 ignition coil with the igniter circuit. This issue you are having purely on the secondary winding which when applies on the plug. The resident transistor is not generating enuf voltage to the primary coil. Replace the one and see the difference. And also the one which you removed #3 OEM chk. Resistance values with No#1 and #8.
Also you need to chk the freeze frame data with the OBD scan tool II. And check the engine temp and fuel air ratio whether are they lean or rich.

cggeo555

Thanks mann777,

I was under the assumption that cylinder F is cylinder 6 in the firing order diagram below. I replaced number 6 on the diagram. Am I wrong in my assumptions? Thanks.