low idle and cel

nine23

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For the F20B and H22 swaps... HELP
I had a ulev in before the swap and I am having the worst time with my idle once it warms up... it idles down really low and sometimes stalls when i rev it up while idling or coming to a stop at a stop sign. I have research so many different forums and it seems like there is a lot of people who have this problem but no one even gives me a solution to the problem that i havent already tried. I have a CEL and the code im getting from the CEL flash test is
41 P0135 Front HO2S Heater Circuit Fault (Sensor 1)
41 P1166 Primary HO2S (No. 1) Heater System Electrical
41 P1167 Primary HO2S (No. 1) Heater System
I put a brand new front O2 sensor from an F23A1 and its still throwing a code, then i added 1 and 2 spark plug defusers and still had the code.... finally i pluged the hole and let the O2 hang with still getting a code... im hoping this is why my idle is why it is but i have to get the code to go away to see if it is.... any suggestions?! also im running DC Header w/ downpipe with a test pipe back to 2 1/4 back to a Greddy muffler if that matters... PLEASE HELP!!!
 

james'99

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I am not familiar with the swap end of things, but I can say that the O2 sensors of the ULEV cars and the LEV cars are not interchangeable. The ULEV cars, F23A4 use a different O2 sensor than the F23A1. You will get those codes otherwise. That's where I would start looking.
 

nine23

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I am not familiar with the swap end of things, but I can say that the O2 sensors of the ULEV cars and the LEV cars are not interchangeable. The ULEV cars, F23A4 use a different O2 sensor than the F23A1. You will get those codes otherwise. That's where I would start looking.

yeah I know that's why I changed to a none ulev o2 sensor because of the swap. from the research that I have done it looks like just the non ulev should work for the swap.... just wondering if anyone else has ran into this problem and what they did....
 

xci.ed6

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Sounds like a wiring prob. What did you do to wiring?

Get dvom, at o2, chassis side, measure volts and ohms to engine block, key on! LMK
 

nine23

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Sounds like a wiring prob. What did you do to wiring?

Get dvom, at o2, chassis side, measure volts and ohms to engine block, key on! LMK

didn't change the wiring for the o2 sensor... distributor changed to 4 wire and had to repin to get the fuel pump to turn on
 

nine23

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Should be 4 wires, 2 gnd, 1 power (heater), 1 signal

kinda took me a while to check it but there was a red, white, blue and black and the only wire showing power was the white wire. it read at 11.82 volts..... this is driving me nuts! :banghead:
 

gsrteg

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If you have a OBD2 scanner that can pull up some live data, that would help also. Try to see if you can borrow one from a shop or someone, and pull up the live data for the O2 sensor. See if the Primary O2 sensor is fluctuating like it should between 0-1Volts. And the secondary should have a steady voltage reading (roughly a steady voltage of .6 or .8 Volts). I remember in my Automotive Performance class, things that can throw or trip the O2 sensors are if you have a leak, vacuum leak, or faulty O2 sensor it self. Just think about it, the O2 sensory is there to monitor the amount of oxygen being expelled out of the engine. If it senses anything more than what your engine is taking in from the Intake manifold, then it will throw a code eventually once it is running and adjusted in the long term fuel trim.

Check to see if you have a false oxygen reading somewhere. Are there any cracks or leaks on your headers/exhaust manifold, or mating of cylinder head and header? Any false oxygen reading will cause the O2 sensor to trip.

Try to get a Freeze Frame of your car from the OBD2 scanner, and try to decipher that too. It shows your Long term Fuel Trim and Short Term Fuel Trim.
 
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nine23

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I have been researching like crazy and it seems like if im not getting a voltage reading from the signal wire that could be my problem if im not mistaken.... the idle problem that I am having is after the engine has warmed up I rev it to a higher RPM and then let out on the gas and the idle drops and stalls.... from what I have read is that the signal wire starts working when the engine warms up (which I have not tested with a warm engine). I have also read that the signal wire should read at 3 volts but I don't know if that is while the engine is cool with just the key turned on. So if this is the case then my thoughts are that if I can get the signal wire to send to the o2 sensor then it should in theory fix my problem... its as if I don't have an o2 sensor there at all right now... I am not going to really be able to dig into it until sunday because of work and watching my daughter but What do you guys think?!
 
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