Just bought a 528i, couple of questions

[jasonhowe]

hello everyone
I just bought a 6/1998 528i. When I tired to smog it codes p1475 and p0155 came up. I replaced the o2 sensor for 0155...which is bank 2 sensor one and it ran noticeably better for about 20 miles then right at 65mph 2500 rpm it hesitated or misfired consistently but only at that spot and of course the check engine light came back on. Now it does the same thing randomly between 50 and 65 mph usually with a slight load on the car (hills). Do you think it could be related to the fuel leak diagnostic pump? It seems more likely to be a vacume or spark issue in my mind...I just find it really strange that the problems occurs so specifically. Thanks!

-jason

[Evilyeti]

Well, a fuel leak would cause poor running under load, due to low fuel pressure. But, on an M50 i had a simmilar problem, that came and went, and it turned out the be the MAF, no codes, but testing it, there were some strange spikes in the graph at certain points in the rpm range.

[edjack]

What codes are you getting now?

[jstern]

P1475=leakage diagnostic pump reed switch did not close. You need to replace this pump. It's part of the fuel evap system. I don't know if this failed part would cause misfires/poor running.

[jasonhowe]

What codes are you getting now?

I'm getting the same codes I was originally getting, plus p1189 which indicates a problem with the air fuel mixture to bank 2. I read that code commonly is triggered by a vacuum leak (I plan on checking the common spots tonight) or aftermarket intake systems (which my car also has thanks to the po.) Has anyone else run into this code?

An additional question
I didn't clear the computer since I don't have any diagnostic software. I assumed it wasn't necessary since the cel turned off after the repair. Is this most likely why I am still seeing the o2 sensor code? I'm new to obd2 bmws.