'94 960 with intermittent and elusive codes 212, 113, and 115. Recommendations from previous posts included cleaning connectors and grounds, which I did today. I also reversed the two relays on the diagnostics tower. Codes are clear, for the moment. Time will tell if they come back or if I fixed the problem.

Some questions:

While working on the car, I removed the air coupler from the air box to the intake manifold to gain access. I was able to peek down the intake manifold by opening the butterfly valve. Noticed some carbon buildup, so I sprayed it with throttle body cleaner. But there is a puddle of oil at the bottom of the intake manifold, near where the power stage modules are. Is this normal, or is there something else I should do for maintenance?

I unplugged each electrical connector to the fuel injectors to clean them. It made me wonder about cleaning the injectors, and I read the info on the FAQ. It sounds like I don't want to remove the fuel injectors unless I have replacement o-rings. Is this something I should do? If so, what parts and procedures should I follow?

I couldn't figure out how to remove the fuel rail. I popped back the aluminium cover and could fold it partially back, but could not remove it. After removing the three bolts holding it on the bottom tabs, how does it come loose? Do you just wiggle it until each of the six injectors pop out, or is there more to it?

Thanks in advance for comments, suggestions, and instructions.

Robert