Samurai 20V Posted November 19, 2011 Share Posted November 19, 2011 (edited) Hi guys.. I fitted a Mines ECU to my car today, having some issues... The car ran perfectly initially, it was pissing down today so I just went for a small drive, it was boosting to 0.8bar fine.. I took it out for a spin just now, when my wife jumped into the passenger seat the idle dropped but returned to normal... Then around the corner, the ECU+MIL light came on car had no power, managed to get it home.. Checked the wiring, the Boost pressure wire had pulled loose (cut from fitting BCC with stock ECU).. Repaired that and now it has error code 21, oxygen sensor, idle is rough, the AFR gauge is reading lean, then goes off the lean scale.. If I blip the throttle AFR drops down, but then returns to lean... The O2 sensor is new on the car, just fitted 2 month ago.. Any ideas? Edited November 26, 2011 by Samurai 20V (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 19, 2011 Share Posted November 19, 2011 See if the O2 sensor is still working either with a digital multimeter or preferably a `scope. Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted November 20, 2011 Author Share Posted November 20, 2011 See if the O2 sensor is still working either with a digital multimeter or preferably a `scope. Ok, looks like the sensor is stuffed... It is showing 0.02V on the multimeter.. When the boost pressure wire pulled out yesterday, the car went mega rich.. Running 10 on idle, maybe that stuffed the sensor up? Is there any way to save that sensor? I paid a small fortune for it.. Should I fit the old sensor back on? Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted November 20, 2011 Author Share Posted November 20, 2011 Drove the car abit today... Idle AFR is back to normal, fluctuates between 14.7 and 15.4.. Cruising is around 14.7, Full throttle drops to 10.. I measure the O2 Sensor voltage again, 1st time it was fluctuating between 0.1V and 0.9V.. Next time it was reading 0.2V.. Given the price of a new OEM sensor, I am looking at buying a Bosch universal Sensor. Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted November 20, 2011 Author Share Posted November 20, 2011 Ok, more investigation on this.. I checked the diagnostics, it showed code 21. I cleared the codes (pulled ECU fuse), bridged TE1 and E1, turned the key to on without starting. The ECU flashed the normal way, showing that there is no codes.. Then abt 5secs later the code 21 started flashing... Help! Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted November 20, 2011 Author Share Posted November 20, 2011 (edited) Did another check, put the old ECU back.. Error code is gone, but O2 sensor metered at 0.08V to 0.9V... So I think it is stuffed.. I reckon the Mines ECU requires a more stringent value for the 02 sensor? 30000yen down the drain on that... Gonna buy the Bosch universal one and try that out.. Edited November 21, 2011 by Samurai 20V (see edit history) Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted November 21, 2011 Author Share Posted November 21, 2011 Just read the that Denso make an exact equivalent.. Gonna look for that as well.. Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted November 26, 2011 Author Share Posted November 26, 2011 Ok...Latest situation - I need help!!! (Mines ECU is fitted to the car) 1. Changed the O2 sensor - Fitted the Bosch Universal... 2. Started up after clearing codes, the ECU light flashes normally twice, then picks up the same code 21, Oxygen sensor.. 3. Drove at full boost, running 11's and 10's.. 4. Then cruising home the car went lean, AFR was 15 and above all the way to 18.. I was on very light throttle and low revs, below 2000rpm. 5. I metered the O2 sensor, its reading 0.12V, which is better than the previous sensor but the car is now running leaner.. Question 1 - Driving the car in that lean state, would any damage have been caused? Question 2 - What do I do now? Help.. Quote Link to comment Share on other sites More sharing options...
FOSTA Posted November 26, 2011 Share Posted November 26, 2011 Mate I'm sure my lambda reads 0.02v when warming up but after a drive it goes up to 0.22v I think I will check mine in a bit and report back to you Also you said it was fine before you wired up the mines ecu but then you started to have problems as you found a broken wire the the code 21 came up! If I was you I would check over all the wires and redo them for piece of mind! Just incase when fixing that one wire it could of disturbed another ;-) Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted November 26, 2011 Author Share Posted November 26, 2011 Mate I'm sure my lambda reads 0.02v when warming up but after a drive it goes up to 0.22v I think I will check mine in a bit and report back to you Also you said it was fine before you wired up the mines ecu but then you started to have problems as you found a broken wire the the code 21 came up! If I was you I would check over all the wires and redo them for piece of mind! Just incase when fixing that one wire it could of disturbed another ;-) Thanks mate.. I think you may be right, I was confused abt the stock ECU not storing the code, and the Mines was... The car was running ok with the old sensor this week, just O2 sensor voltage readings were not within spec.. It may be a wiring issue.. Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted November 26, 2011 Author Share Posted November 26, 2011 Ran the car again just now, idle was fine, drove around on the low revs and throttle car was perfect.. AFR - 14.4.. With some throttle it drops down to the 13's.. Whilst parking it went crazy lean and the idle went rough, revved it and back to normal.. Metered the O2 sensor, switching bet 0.4V and 0.7V, but there is one point were it hits 0.02V... So I reckon the old sensor was stuffed, I will recheck the ECU wiring.. Quote Link to comment Share on other sites More sharing options...
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