Solid20vq

Wow, I can see why they stopped making the one piece knock sensors; quite a PITA to deal with! But it only took about 35 minutes to remove. I'll post results once I get the new, bolt through sensor installed. Pretty sure this will solve my problem. (please God!)

yodasfro

Torque spec for the bolt is 15-18 ft. lb's It's critical that it is torqued properly.

Solid20vq

Yes sir, hand-torqued her to 16.5 lbs/ft, as per spec It works great, however perhaps a bit shorter than the one-piece sensor; I had to unseat the receptor plug to connect her. M8 x 1.25 - 25mm screw from Ace $.89.
In order to replace the rear sensor, I had to unbolt and wedge the fuel pressure regulator and unbolt a wire-harness plate from the intake manifold.
Power loss symptoms have been resolved and gas mileage has vastly improved. I still have a CEL, 2114 I believe, which is representative of "basic ignition" or Hall sensor misalignment (??). A replacement ISV is on its way, and I'll worry about diagnosing the remaining code(s) once it's installed.

Rennkafer

I've seen a couple cases discussed over on Motorgeek where the hall sender in the distributor was loose/bad and caused problems. I have to make a test rig to pull the codes as mine won't hook to Vag-Com for some reason (using the 2x2 adapter and current Vag-Com release). My car also pulls timing somewhat randomly and like you I changed out the knock sensors which seemed to relieve the problem initially but now it's back to doing it again.

I only paid $800 for my 90Q though... so I knew what I was getting into

Oh... and it's a 7A engine, not an A7.

Solid20vq

Copy that 7A, one day I'll work up to an A7

That's funny because I also paid $800 for my 90q. Replaced the timing belt and water pump ASAP. I also had to replace a faulty fuel pressure regulator, which was causing a super-rich mixture(enough to destroy the O2 sensor).

I've just been pulling codes with a home-made blink tester (VAG1115), and I don't really know if I went through the output proceedure correctly to clear the knock sensor code.

yodasfro

If you pull the ECU fuses under red cap labeled motor it will erase the faults codes. Keep them removed for 10 or so minutes for it to work.

Solid20vq

Most helpful, thank you sir!