Code P1072, running too rich.

[furtula]

I'm opening a new topic since the old one is confusing and i wrongly put incorrect code.

 

Yesterday the car was feeling hesitant, and felt underpowered, but no codes. Was doing mostly city driving and thought maybe a bit of higher rpm could fix the issue.

Initially, on startup  it felt fine (was already partially warmed up),idle dropped 2x to 400, then went back up, but after few minutes, i presume when reaching running temp, i got code P1072 sensor 1 bank 1, car running too rich.

 

When starting cold today (i deleted the code earlier), feels fine, runs fine, idle ok and steady. I presume this is because it has some default parameters it applies. But i guess once it reaches running temperature, the code will (eventually) come back.

My suspects are MAF, or maybe O2 sensor. Am i right to assume car ignores one, if not both values until it's warmed up, using some predefined values?

It does not seem logical that it's the fuel delivery system, since it says it's too rich, so i presume that part is fine. I know you can try to smell the gasses when warm, but the car is sitting, for now.

Also, i haven't checked O2 so far due to it's rather inconvenient placement, both with the connector, but if it actually reports the rich mixture, and since there is no code for it, maybe it's ok.

 

Just wanted to check if my logic makes sense, and what others think.

 

 

[Konrad C]

What you need is live scan data. Then you see what everything is doing. I don't really understand all the data, but there should be general figures to give you an idea. My Avensis has the 1.8 Valvematic engine, which is similar. I will see figures are showing using my Launch or Techstream. 

[furtula]

Just a short update in case someone else might have this issue in the future..

 

After i deleted the code, it has not come back. Some 3-4 starts, mostly short trips + heavy pulls, and a bit higher rpm here and there to see if anything happens, so far nothing, MPG is normal.

I established that the car runs great on cold, or for 10 seconds or so when warm, but  restarted, and sluggish on warm, which i presume is when the pre defined variables are used, instead of a closed loop and calculations based on sensor data values.

My suspicion is still on MAF, but im waiting for a cleaner to arrive. 

Air filter ok, service done 5 months ago, new NGK spark plugs also fitted then, cca 2.5k miles or so.

 

 

 

[TonyHSD]

Cool, have you clean your throttle body on regular basis, if dirty this may well been the source of your problems, there is a MAP sensor nearby is good to get it clean too with spray egr throttle body cleaner. Maf sensors I think require a different spray. Usually when throttle body is dirty cause trouble when car is hot in hot sunny days , when cold no trouble. Good to check , just in case. 
Regards 

[furtula]

To update the topic.

After cleaning MAF, which was not really dirty, i have been driving the car for 2 weeks and the code has not come back.

The car was still slightly sluggish when warm, but i started to drive it much more aggressively, and the ECU adapted, feels almost normal, or normal now, can't really tell.

I did not want to take the Battery off to reset it because of the radio, but that could also be a potential solution.

Also, the car has more even note when revved into higher RPM, sounded a bit harsher before.