Ive had a code 44 popping up now and again for a while but just recently it has gotten worse. It only happens at idle as soon as it hits open loop - idle hunts and then sets off the code and it goes into closed loop. Doesnt do it in closed loop.

O2 sensor is new and not touching any part of exhaust, still does it when the MAF is unplugged, injectors have been cleaned and tested - one flowed too much so has been replaced with a brand new one, fuel is fresh, fuel pump gets enough voltage, exhaust is new (with ceramic coated headers), cant find any vacuum leaks and there is no AIR system.

What am I missing???

 

Check your fuel pressure.
Also start looking for any kind of vacuum leak.

 

Thanks for the suggestion. If it was low fuel pressure, wouldnt it run poorly in open loop too? It runs perfect when i keep it in open loop using the ostrich.

 

do you have still have the cat on the car ? make sure the bolts are tight at the collectors if they are loose possible you could suck in fresh area and make the o2 sensor read wrong and if they arent tight on the heads. low fuel pressure could cause this. make sure u dont have a bad place in ur o2 wire.and also make sure u dont have any crimped vaccum hoses.

 

no cat and everything seems tight. I think i found the problem - a 2 prong connector near the distributor was disconnected. Plugged it back in and no more code 44, idle is smooth in closed loop. Anyone know what the connector is? Maybe the MAT sensor connector? (car has been converted to RHD)

 

Looks like the EGR solenoid.

 

thats what someone else said. thanks, car is back to normal now.

 

Well thought it was back to normal till i let it idle in Park. RPM jumped up and down a bit, SES light came on, then it went to open loop for a few mins then back to closed loop and light stayed off for the remainder of a 15 minute drive.

I'll have to do more tests to see if it only happens in park.

 

happens in drive and park again now. i just cant figure this thing out

 

i think i need a heated O2 sensor.

After watching the O2 mv in tunerpro, they slowly (very slowly) climb the longer the engine is on. After a bit of highway driving, its switching lean/rich nicely with good mv readings including at idle. if i start the car a few minutes after shutting it off, the mv reading is really low again and takes time to increase... of course the engine temp is still up, so it goes into closed loop very quickly not giving enough time for the O2 to warm back up again.

Does this sound right?

 

That does sound like a lazy O2 sensor. But could be bad grounding for the sensor, especially if you have headers and/or exhaust manifold gaskets....
If you decide on a heated one, go opt for the 4-wire (heater +, heater -, O2 sensor out, O2 ground.)

This will allow you to put the sensor anywhere in the exhaust, and have a good ground back to the ECM.....

 

another thought, maybe im running too rich at open loop?

is there a simple way to reduce the fuel in open loop? Im running a stock 89 350 bin (6e) in the ostrich. the engine is a 1990 350 but still using MAF.

 

Got the heated O2 installed today, warms up in about 10 secs... compared to my old one which took about 10 mins!

No more code and a steady idle when it hits closed loop.

 

whats the part number on that heated sensor you bought?