Sorry it took me awhile. A bit busy at work... Anyways, as you assumed, my Hitachi MAF only has a 4 wire connector instead of 5 like yours. Sorry can't be of help.

 

Appology not accepted.
You've helped me by providing the connector p/n when dealer gave me the wrong #. Thanks again for the replies to my past questions, & of course the future ones to come.

 

Hey Cruby, I'm having a similar issue with my CMP sensors throwing a P0341,P0346 code, how did you align your sensors correctly? I'm thinking this is my issue.

 

I may not be the best to take advise from, since I'm still throwing code:
1My manual says this for your codes:
P0341 & P0346: Camshaft Position Sensor (A) Circuit, Comparison to engine speed sensor - No altering signal at reference gap.

Best I can tell, the CMP sensor goes on only one way, so it's unlikely to be installed incorrectly. Beneath the CMP is a sheet metal cup with a big slot in it. This cup is bolted to the cam & is clocked to it with a tab that seats into another slot on the camshaft. Again, only one way to put it on correctly.

 

On jack stands I mean. Lexus in for PS pump rebuild & serpentine belt/tensioner/pulleys change.

I was putting A6 on hold, but son finished assy & we test drove last night. Idles a bit rough & I can detect misfires. Didn't Vag-com it then, but will this weekend. However, when it revs above idle seems to run smooth. Ran great in the test drive, except for idling. Now I need to figure out what's causing idle only misfires, & if it's limited to either bank.
FYI, new ignition parts include: 2 ICM, 1 CMP sensor, repaired MAF connector.
Plugs & coils look good & tested OK.
I thought TB was aligned dead on last time, but still throwing Incor. Correlation bwtn G40 & G28. Possibly a 3rd teardown in order to recheck...again.

Any clues on idle only misfire causes?

 

You asked for it... The only thing that I see with the timing issue is the cam chain spacing.

As for the misfire, it can be related to the timing issue. Another this is the throttle body alignment. Did you do one since all the repairs?

 

Throttle Body Alignment?
Nope, didn't do one & need to do some search on what exactly I would do. Is this addressed in the repair manual?
I have nighmares involving cam chain spacing...so I'll avoid that subject for now, although I know I have it consistent with what's shown here:
Engine assembly specs, tolerances, tips, diagrams and links document

 

If you have VAGcom, then it is one of the functions in the measuring blocks. I forget which one. If I am too lazy for pulling out the cable and the laptop, I just disconnect the battery. Wait 5 minutes. Reconnect the battery. Turn the key to the ignition on position without starting the car. You should hear a faint motor noise coming from the car. Let it do its thing for a couple of minutes and you should be good.

 

Oh, I just realized that you may have throttle body with cable. I think the method that I mentioned works, but the sure fire way is to do it through VAGcom. Here I got unlazy.

Throttle Body Alignment (TBA) - Ross-Tech Wiki

 

Going back to the cam chain tensioner alignment... I know you have nightmares, but you still have to fix it you know.

One, try running through the cam shaft adjustment check. It is under 04, Basic setting, display group 094. You should have a description on your manual.

If checks out okay, then you pretty much eliminated the issue to the cam chain only. I would try to solve this in an intuitive way, not by the stinking manuals.

Since you are using old chain and your chain tensoner padding maybe worn and etc... the roller count may vary. One thing to keep in mind is that the manual specified that the roller count is for a new set of chains. Who knows how much the old chain would have stretched. Align the cams and verify that you have the notches on the cams align with the arrows on the rear cam caps. With the timing belt and the chain tensioners fully installed, rotate the crank at least 5 to 6 revolutions. After those revolutions, you should have the notches on the cams still in alignment with the arrows on the rear cam caps.

With that said, if you can't sort something out after that, I will shut my mouth. I am out of ideas too. Good luck.