98 740iL - Big repair bill and still getting codes!

My 1998 740il has 171k on it, mostly highway, and drives very nice. I purchased it about two months ago, with a check engine light on for $2500. So, I knew I would have to spend a little money on it. It's clean, rust free, and everything works. I am very happy with it.

However...I took it to a shop recently, after using my Peake tool to pull codes (misfire, pre-cat o2 sensor aging, etc) that looked a little past my DIY skill level. I was told I needed to replace one o2 sensor, as well as the intake manifold gaskets. Oh, and that the valve covers had to come off anyway (my gaskets were leaking, but I didn't want to spend the money right now) so they would do those, as well. By the time I realized the valve covers did NOT need to come off, it was too late, they had pulled the covers.

I picked up the car yesterday, and it was running well (I want to say it had more power, but I had been driving my brother's not very fast Ford F250 Super Duty for 10 days...so...). The check engine light was off. $1450 and 10 days later, I took my car home.

30 hours and maybe 50 miles later, the check engine light is back on again! I scanned the codes tonight, and many of them are the same:

28 Catalyst Efficiency, CYL 1-4
2d Catalyst Efficiency, CYL 5-8
23 Fuel trim, QL additive, Cyl 5-8
16 Pre Cat 02 sensor aging, Cyl 5-8
3e Misfire, random or unknown cylinder
32 Misfire, Cyl 1
34 Misfire, Cyl 3
33 Misfire, Cyl 2

I hate to jump to conclusions, but I feel scammed. Thankfully I paid most of the bill with a credit card. Do I bring the car back to these guys, or do I run and go elsewhere? I would think I can dispute the charge (or a reasonable portion of it) if I find that the repairs did not solve the problem. I won't get into the fact that they broke the plastic engine/intake cover, left off a plastic tab on the right valve cover, and broke my battery terminal cover on the right valve cover. Or, that they told me the bumper had to come off to replace the right headlight (my friend did it in 10 minutes, in his driveway, while I watched...).

Any feedback would be appreciated. I am trying to remain calm, but I am pretty annoyed...

You paid for them to provide you the service of fixing your car, they didn't fix it, you should definatly bring it back and inform them that not only did they not fix the car but they broke parts that were just fine before they put their hands on it.

I called the shop owner, he started screaming at me - insane. He later called to apologize.
A few days later, I sent him photos of the broken plastics, along with photos of oil soaked plugs (he apparently did not bother to mop up like 8 ounces of oil puddles in the valve cover after changing the gaskets...) and he hasn't replied to my email or phone message.
I'm just going to dispute the charge. Pathetic.
Vanderveer Motors in Norwood, MA. I certainly wouldn't recommend anyone go there.
(The owner has been an aquaintence since the late 1980's, which made this even more strange)

I am sorry to hear that a shop can treat you like that. Sadly, that's just the way it is around nowadays.

Try to avoid putting your car in the shop from now on. Atleast that way you know that what ever is being done with the car is with your own hands and tender love and care. I understand that you have some mechanical skills since you own the diagnostic tool allready. So let's cut to the case..

#1. Is the car burning any oil?

#2. Is the car smoking? And if so, when? Startup, high RPM?

#3. Does the engine loose all it's power after a high RPM acceleration?

If any of these are a part of your problems, I would definately have a look at the CCV valve.
I have had the same codes on my E46, and it turned out to be the CCV. It may also be a major leak in the intake boot that you might have overlooked. That could also trigger those misfire and O2 sensor codes. Have a real good look at those boots.

Let me know..

By the way.. It must be the boots or some gaskets in your intake somewhere.. A leaking intake will trigger those excact codes..