How many miles are on the engine? How does it idle? Steady? What do you mean Bogged down? Does it ever die?

First, make sure you have the correct O2 sensor for your car. My Euro 500 uses a one wire Bosch but I don’t know the 560.

In the words of the local dealers shop foreman “It could be a lot of things. We usually have to change a lot of parts so it cost s a lot of money and people don’t want to pay”. I said “that is me exactly” and he took a pass on my (Gray Market) car.

I fixed everything over time, by myself, but it took me a long time because I am a total amateur and I did have to replace a lot of parts and they were rather expensive but the results are great. Good luck.

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Steve
1985 Mercedes 500SL Euro (Gray market)
1995 BMW 520i Euro (Gray market)
1992 BMW 525it Wagon
1994 Honda Del Sol Si