Error Codes 41 & 55

[caballerosensual]

I have a 1994 Lexus LS400. I've been having performance issues with an engine remanufactured last summer due to a blown rod bearing at 137k miles. The car's performance is suffering greatly as it can't accelerate. I thought it was the cats, according to web research. Both catalytic converters have been replaced but the problem still persists. Yesterday, the service advisor stated that codes 41,25,26,71, and 55 were stored in the diagnostic computer.

The codes were cleared however codes 41 and 55 came back. I called the Lexus dealership to inquire about the TPS and the shop foreman recommended cleaning the throttle (plate) body first. I was told by the engine builder today that they do not always clean an engine's throttle body, thus it "may" be dirty. I'm reluctant to pay for more services that may not work however I need to get this car up and running ASAP.

Should I move forward with purchasing the TPS & replacement knock sensors in addition to having the throttle body cleaned or clean the throttle body and go from there?

[Yamae]

Sounds like an ECU issue to me.

[caballerosensual]

Sounds like an ECU issue to me.

Hi Yamae,

Thanks for replying. Would you care to elaborate?