[malibumlk]

Hikin,
Thanks for the follow through.....much appreciated.

I checked the TVV this weekend....and as you suspected......it was closed tight as tight could be. Odd thing though, I had a re-occurance of code 276d....."tank Vent Valve".

I suppose it is possible that the TVV fails to open on occasion, thus triggering the code, unrelated to the lean mixture codes. I'll deal with that separately if that's the case.

All of the Laen/mixture Prep. codes were present as usual along with the TVV code.

Question: while continuing to search for an external vacc. leak, I had the engine at idle and pulled the dip stick......full vacuum in the crank case. Is this normal, or possible confirmation of internal leakage of the Oil Separator valve?

Next question (and after the Q? above): In review of the Vacc/ intake system, I don't see a possible external air flow path from an internal failure of the Oil Separtaor Valve.....where does the vacc. air flow originate if the system is sealed and the crankcase is at full vacc. pressure (negatve pressure) ??

Is any of this pointing to the conclusion you came too on your recent customer car.....i.e. internal leak of the Oil sep. Valve????


Thanks Hikin.........big disapointment on your customer car that we couldn't see it through.

Mike