I have just replaced my ‘02 xkr’s throttle body with a newly rebuilt one. I replaced it as I was getting rich codes 172 and 175. The new throttle body alleviated the codes but I am having problems with the idle. I can’t get the idle below 800-900 rpms. Do I need to reflash the ECU? Will running for a period of time allow the ECU to adjust the idle over time? Any help is appreciated. The throttle body is spotless and the sensor is good. I also replaced MAF just in case.

 

Sounds like you got a vacuum leak.

 

Really good thought but I actually tested for a leak when I got codes 172/175 and also checked the valves before I replaced the throttle body. There was a small leak which I repaired and a slightly sticky valve which I also repaired. I just can’t get the idle down. I may just try driving it more to see if the ecu will “learn” a new throttle body or try to find a way to reflash the ecu. Not sure what else I can do at this point.

 

Sounds like the 'rebuilt' one needs a feedback pot adjusted.

I only ever installed FACTORY REMAN or good used so I never had this sort of problem.

 

pps cable is probably way high. go adjust it

 

Yes, you checked for leaks BEFORE you replaced the throttle body.
My thought is that you got a leak with the new throttle body.

 

From memory, there is a video on youTube describing a procedure on an XK8 where the sensor is loosened and manually adjusted for idle speed...

 

Mine is a N/A 2000, don't know if the TB is different on the S/C models. But the throttle cable has to be adjusted to have zero slack, but at the same time the throttle has to be completely closed. When I removed my TB during octopus hose replacement the cable got slightly out of adjustment, causing a similar problem.