I have a 06 r53 with 65k miles on it -has served me incredibly well for the last 4.5 years but today the eml light and check engine light came on and car lost power down to 20 mph.I am looking for suggestions on to what could be wrong -its been extremely hot and humid here( in NY) for the last month or so. had no warning signs but was sitting in traffic

 

You need to have the OBD code read. If you feel like driving the car, you can go to an Auto parts store like AutoZone and they will read the code, generally for free. If you do not want to drive, you will either have to have the car towed to a mechanic, or find one that will come to you. Once you have the code, it can tell you what is wrong. Also, when the engine cuts power like that, we call it "limp mode"

 

P1125 and 0638 appears to be an issue with throttle cxontrol?? Which after searching some other posts appears to be most likely a wiring harness replacement??]

 

it seems the connection was loose on the cable itself which caused the car to read the error codes I disconnected and reconnected the wires then cleared the codes and everything is running strong.

 

Glad you fixed it. I had read other posts where that was all that was needed... a quick reseating of the harness plug.

 

ok sorry guys I am back, car is still running strong but SES light came on again coming up with same 1125 code. checked connections and they are all good REALLY dont want to go into the dealer-Thanks again

 

It is possible the terminals in the harness plugs are dirty or corroded. Unplug it and check for signs of this. If dirty, clean with a can of compressed air. If corroded, the male ends should be easily cleaned with a brass brush. The female ends will be a bit more tedious. You will need a round jeweler's file. You should be able to find a set at an arts and crafts or hobby store.

Beyond this, it's possible the harness is defective and needs to be replaced.