Mess of problems w 2000 s80
 

Hello all,
I'm a new Volvo owner - just bought a 2000 s80 2.9 w 64,900 miles. Initially the car was surging when idling, and occasionally stalling out while idling. CEL was on. I cleaned the ETM (which is a miracle considering my mechanical ability) but the engine was still surging while idling. I took the car to AAMCO to get the codes read (262A and 272A - both LT fuel trim codes). They told me it was a leak in the intake. I went to get a second opinion at a euro specialty place and they found the additional codes 9150 and 903F (both throttle unit codes). The specialty shop said the pcv system was leaking and needed to be replaced ($1050) which would also require an induction cleaning ($230) AND the MAF sensor needed to be replaced ($425). The shop was adament that I would not be able to do the repairs myself so I went ahead and let them bend me over for $1800. The surging was gone. After all that I thought I'd be able to pass emissions and be able to register the car and everything, but the CEL came back on after less than 20 miles, Flashing this time. I probably would've taken it back to the shop but they're closed on weekends so I read some posts and narrowed it down to an ignition coil, which I replaced myself for $60. The CEL stopped flashing and the engine sounded much better. Read the codes today at the auto parts store and there was a P0301 (misfire cylinder 1) which I think I fixed by replacing the coil. No other codes came up besides the misfire. I've driven about 10 miles since clearing them and the CEL hasn't come back.

So, I'm wondering - 1) what happened to the other codes for the throttle unit that the shop was talking about? Why were they gone when I read the codes when the throttle body hadn't been touched?
2) does it sound like the issues are gone or should I expect the CEL to come back?
3) the shop is recommending I replace the ETM as well as a number of other things (total shocker) including flushing the brake fluid which "fails test"? I didn't even know there was a brake fluid test. But why would I replace the ETM when it's not showing the codes anymore? Are they just trying to milk me more than they already have?
4) how did the shop not notice the bad ignition coil? The engine definitely sounded like it was struggling.
5) has anyone had similar problems? If so, how did you fix them?

Thank you for any help/advice/feedback and I'm sorry for such a long post. I really like the s80 but it seems insanely expensive to fix anything in it. I'm not going to be able to put any more money in it for a couple weeks at least so I'm strongly considering just doing everything myself going forward.

Thanks

9150 is a throttle code and the throttle will likely need to be replaced.

Brake fluid won't cause any emissions problems or warning lights, but it should be flushed if dirty.

Coils are very common. It is quite possible the coil was firing when the shop had it.

Your car has one of the design defect ETMs. Xemodex can repair it for you.