Can you read oil temperature? About the only thing I can find that would inhibit the high lift cam profile switching is an oil temperature below 20C. I would assume the solenoids that activate the switchover, are monitored for shorts and opens by the ECU so there should be some kind of DTC if those were electrically bad.
2006 HSE Bonnati Grey/Charcoal Interior
It is strange, but maybe the parameter I selected was wrong? But I followed 2 parameters - one for the position, and one for the request, neither every moved away from the "low" setting even at WOT/Redline
Typically, when an issue is detected, the system will generate a "freeze frame," which will store all of the engine parameters at the time of the event. What I suspect here is an issue of ignition misfire, either due to coil packs dying, or leaking spark plug wires. What I typically see with engines with more that 50-60,000 miles on the clock and a misfire, is that the spark is leaking around the plug wires to ground, or the coil is arcing internally. There are several things causing off-idle misfire; one is that the mixture leans out off-idle. Yes, it stays at 14.7:1, but there are issues with effective compression, in other words, better cylinder filling off-idle, requiring more spark voltage to fire the plugs. The other thing causing higher effective compression is spark advance, which again raises effective compression. So does the cam timing, as it is creating EGR, which controls NOx. All of these conditions raise required voltage, and the resulting higher voltages can stress ignition components to the point of arcing. It is also possible for one or two plugs to have cracked insulators, causing arcing. If the codes indicate which cylinders are misfiring, you can use the codes to isolate the faulty components. Chances are that if one or two cylinders are the culprit, the others will soon follow. Ray
I am not getting any misfire codes.. Just have tried to see if any are showing up. Plugs and Injectors are new, i think coils are original.. although I would think a bad coil would throw some kind of code.
They are telling me that due to the bad CAT.. (P0420), the tune is being thrown off. I have a hard time believing that. He says the system is constantly pulling timing and enriching/leaning the mixture in order to determine if there is a misfire or other issue and develop another code.
One thing I noticed while perusing the previous pages was the apparent disagreement between TPS readings. Does this engine have two throttle bodies? Can you clarify the two TPS readings? I tend to agree with you re: the cat issue, but if one side is partially restricted, the resulting imbalance in the exhaust may cause the ECM to start "guessing" about what is going on. Let's start with the TPS issue. The Po420 code relates to the cat's ability to store O2. If the system is attempting to provide more O2 to that cat, it WILL lean that bank in an attempt to provide more O2 to that substrate. That makes more sense to me that the gibberish the tech handed you. Ray
The downstream O2 sensor connectors attach to mounting clips close enough to each other at the rear of the transmission that you could easily mark them and then "swap" them (the connector plugs) Left side rear O2 to Right side rear O2, and Right side rear O2 to Left side rear O2, and see if the "cat problem" compensation swaps sides too.
What were the results of the compression test?
While waiting for the cat., I am going to continue to monitor other parameters to see if I notice any more anomalies. I am getting 1-4 misfire counts every now and then on Cyls 2,4,6,8 (note, I am only monitoring that side, for misfires resulting in catalyst damage, and misfires resulting in emissions problems, 2 parameters per cyl, max 8 on IIDtool). Cyl 6 seems to be the most finicky, followed by 4 and 2. Misfires are mostly when at low RPM /Low load. WOT or high load shows zero. Will monitor bank 1 to see if there is a diff
hmm, I have the same misfires and rough idle for a year already... it all started after I replaced VVTI units and chains + all required parts (guides, tensioners etc)
Another useless update - replaced the bad cat, reset adaptations.. fuel trims went right back to how they were (negative on both banks) Surprise.. but at least no P0420 code anymore. the search continues.
In case I missed any previous reference to the injectors, have you replaced the injectors with new very recently or removed them, had their existing flows checked and or cleaned then re-tested and re-installed?
OK, are you certain that each injector was tamped down into its seat?
They can't necessarily just be inserted by hand and then expect the fuel rail will "seat" the injector.
If you have a "loose" injector you might get this type of issue.
If you are absolutely certain you fully seated the injectors then disregard.
If not, I'd consider removing the fuel rails and pulling the injectors, replacing their teflon seals and re-installing them correctly.
It's also possible to have an occasional faulty injector although that's uncommon. A company in Houston called Injector RX is able to test and service DI injectors.