GS300 P0138 and P0158 reappeared after sensors change.

[AdamQ]

Hi Everyone. New to club but spent most of my life working on cars and driving Lexus.

Hope that someone may have answer to my question about P0138 and P0158 Codes.

Obviously i know those are related to both post cat oxygen sensors and as i have already diagnosed they both were faulty and reading something silly like 7V.

I have already replaced both of them yesterday, cleared codes drove to work (about 30min) no problems.

Or so i thought. Got in the car after work, started engine and after few seconds warning lights came back up. Thought it may be my CVT transmission (btw I'm waiting for solenoids to fix that issue) but no , codes P0138, P0158 came back.

Did scan and live data showing front sensors within spec about 0.7v and post cat 3.3v. Strange thing is both sides are reading same values, pre and post cat.

Anyone ever came across that issue? 

[steve2006]

Hello and welcome to the LOC.

Did you use OEM replacements, I think they are normally Denso?

[AdamQ]

Hi Steve.

No, I used oe equivalent Intermotor. Used them before and never had problem like this. 

Had originals failing in clients cars and it always was a successful fix.(no longer in trade full time)

Shame I didn't read live data straight after replacement to be sure I had them within spec.

Strange thing is that post cats normally pop the fault on cold engine and i had a faultless journey this morning.

 

[AdamQ]

All sorted. Everything went back to normal day after and for all last week no fault regarding lambdas came back.

Strange, but happy with results.