Has anyone else experienced backfires through the intake after slowing down, and then getting on the accelerator? I thought that maybe it was the VVT mechanism so I disconnected and then reconnected the electrical connector. Then I notice that it is hydraulically assisted. I checked my oil and it seemed a little low, so I added a quart, and it helped but 2 weeks later, it is doing it again. Oil level is fine this time around?? Is there a solenoid in the VVT section that could need a cleaning?

My car has 109k on it and I have had it since 91k. The first thing I did was switch to synthetic oil and change the timing belt. I just changed the oil back to dino oil today. Since I noticed that it was using a quart of synthetic oil, as stated above. Any ideas??

 

OK, since no one on this forum answered the call. I journeyed into un-chartered territory on my own. First, I started out by going to my local Checker Auto Parts and borrowing their code checker. It said I had a lean condition in Bank one, but did not pinpoint the CEL further! Browsing the store, I found a small code reader on clearance, bought it and it outperformed their $200 rental unit by a mile. It gave me 10 codes, everything from bank one lean to misfiring on cylinders 1,3,6. It also had codes for random misfires. I guessed that the problem had to be electrical. I checked into the cost and availability of the ignition coils. The parts man stated that the coils were $175 each and were special order only...in addition, they rarely see them ordered. So, I disassembled the intake system to get at my coils. Ran a continuity test of all coils and found them to be essentially the same resistance. Next, I removed all plugs and checked them for resistance between the center anode and the top of the plug. Low and behold, 3 bad plugs! Plugs number 1,3 and you guessed it 6! Now I was getting somewhere. Having tried NGK platinum last year with horrible results, I actually put the NGK dual electrode old plugs back in, so this year I hunted down the NGK dual electrode plugs and replaced all 6, of course. Put it back together, minus, the decorative engine cover and started the car. Sounded smooth, except for the hissing jet sound. I pinpointed it to a double cracked vacuum hose, ell shaped and about 4 inches long. I replaced it, and that hose was probably responsible for the lean condition and the plugs responsible for the backfiring and misfiring. Reset the CEL with the code reader.


Well, it has been 3days and no CEL!!! I believe I licked the problem!!! Total cost $50 including the Code Reader!!

Hope this info helps someone in the future, if so, post here for others with the same problem!

 

Good job on getting your issues sorted out. How much mileage did u have on the plugs? Which NGKs? I got the NGK iridium 9 last year put about 12k on them and they are still performing same as day one.