My 1999 AWD RX300 with 175K sat idle for about a month while I worked on the suspension. When I restarted it, the CEL came on; codes were P1150 (A/F ratio sensor circuit range/performance malfunction, bank 2 sensor 1) and P1155 (A/F ratio sensor heater circuit malfunction, bank 1 sensor 1.) I reset, but within 10 miles the CEL came on again, this time throwing the following codes: P0125 (insufficient coolant temp for closed loop fuel control), P1155 again, and P1153 (A/F ratio sensor circuit response malfunction, bank 2 sensor 1.) I'm guessing there must be a single cause for these multiple codes - any thoughts? TIA

 

Was suspension work all that you did? Anything else or at least remotely close? Perhaps you unplugged a wire to do some of your suspension work?

I'd venture to say that it's your O2 sensor gone bad that's triggering your P0125.

 

Nothing but suspension work. No reason to believe that any wire got disconnected.

 

Electrical connectors can get bumped off unintentionally and unknowingly!

 

Dump some fuel injector cleaner in there. When my RX sat back in late 2007 while we took out the transmission, I had the same type of issue.

 

Lexmex; thanks, but dump the fuel injector cleaner where?

 

In the gas tank when you fill up