THE SERVICE ENGINE SOON LIGHT HAS BEEN COMING ON AFTER 20 MIN OF DRIVING OR IDLING IT ALWAYS COMES ON AT THE SAME TIME THOUGHT IT WAS THE Y PIPE GASKETS BECAUSE IT STARTED WHEN THEY WENT BAD THEY WERE REPLACED still does it i tuned it up recently changed all filters does anyone know what this code indicates its a 90 s15 jimmy 4.3 tbi.
IM GETTING A CODE 44
- Thread starter jc1990
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It means the 02 sensor is reading lean exhaust. Could be the 02 sensor, its wiring or connection bad, exhaust leak upstream of the sensor, a vacuum leak, fuel pressure or dirty injector issue, or maybe the EGR valve is not seating and crudded up. You replaced the fuel filter right? Does it have any other drivability symptoms? you might try running some Techromn through the tank.
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THANX GUYS YES I DID replace all filters the truck runs okay every now and then it will just die when idiling i figured the new exhaust gaskets would fix it since it started as soon as they went ive been running mmo in the gas 4 oz to 10 gallons of gas maybe ill try the techron i know it works pretty good
Originally Posted By: jc1990
THANX GUYS YES I DID replace all filters the truck runs okay every now and then it will just die when idiling i figured the new exhaust gaskets would fix it since it started as soon as they went ive been running mmo in the gas 4 oz to 10 gallons of gas maybe ill try the techron i know it works pretty good
When it quits like that,is the idle normal or lower than usual?
THANX GUYS YES I DID replace all filters the truck runs okay every now and then it will just die when idiling i figured the new exhaust gaskets would fix it since it started as soon as they went ive been running mmo in the gas 4 oz to 10 gallons of gas maybe ill try the techron i know it works pretty good
When it quits like that,is the idle normal or lower than usual?
If you have an exhaust leak upstream of the o2 it can suck air in and totally screw the o2 sensor reading.
Next question is how does it run with the o2 sensor disconnected completely? Should be fairly okay in open loop. If it gets worse you have some other sensor (MAP, MAF, coolant temp) that's out of range and the o2 has been compensating.
If you pull a vacuum line and stick it in a bottle of MMO it will make a nice smoke show and if you have a bad exhaust manifold gasket it'll smoke under the hood too.
Next question is how does it run with the o2 sensor disconnected completely? Should be fairly okay in open loop. If it gets worse you have some other sensor (MAP, MAF, coolant temp) that's out of range and the o2 has been compensating.
If you pull a vacuum line and stick it in a bottle of MMO it will make a nice smoke show and if you have a bad exhaust manifold gasket it'll smoke under the hood too.
HAVE NOT TRYED THAT YET ONE THING IT DOES IS FIRST start of the day it takes longer than usual to fire up usually 10 to 15 seconds before it fires rest of day starts fine been like that since i got it fuel filter is new seems to run good but it really sucks the gas even with a completly new tune up just one more problem to deal with on this truck among the many others
I think this engine has two injectors in the throttle body.If one or both are sticking or dont flow right,that could cause a problem at start up and idle.
NO ITS THE TBI UNIT I ACTUALLY FOUND TODAY THAT MY COOLANT TEMP SENSOR HAD CHEWED UP WIRES PROBALY FROM MICE and found coolant temp sensor to dash bad so hopefully this solves it im also replacing the 02 sensor because it looks origanil see what happens
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