CEL flashes 4 times on startup/ FIXED
03-27-2016, 11:05 AM
#1
CEL flashes 4 times on startup/ FIXED
1995 F150 302 auto 2wd
On startup after sitting overnight the truck flashes the cel 4 times and the engine rpm raises to about 2000 rpm then drops and stumbles then returns to normal idle.
After reading a lot of stuff on this I came across a response that said the 4 flashes is given because raw fuel is getting to the cat. The suggestion was to replace the oxygen sensor.
I replaced the oxygen sensor and everything went away and is now functioning normally.
Just wanted to pass this along and if the person who gave this advice is here, THANK YOU VERY MUCH
On startup after sitting overnight the truck flashes the cel 4 times and the engine rpm raises to about 2000 rpm then drops and stumbles then returns to normal idle.
After reading a lot of stuff on this I came across a response that said the 4 flashes is given because raw fuel is getting to the cat. The suggestion was to replace the oxygen sensor.
I replaced the oxygen sensor and everything went away and is now functioning normally.
Just wanted to pass this along and if the person who gave this advice is here, THANK YOU VERY MUCH
03-27-2016, 10:01 PM
#2
Senior Member
Did you replace the downstream sensor? I'm about to do mine. Probably original, because everything else was on my truck I bought a few months ago; why would this be different? Any issues or tips?
03-27-2016, 10:48 PM
#3
Rod Wise, Mine doesn't have a downstream oxygen sensor. As far as tips go the only thing I can say if yours is as stuck as mine was you will need a lot of patience. I used heat on it and used a hammer and chisel on it to break it loose,once started I had to work it back and forth all the way out. Its a pretty easy job other than that.
Also it might save you a little money by doing this. I bought a Bosch oxygen sensor from advance auto on line, use coupon code trt30, it will give you 30 percent off but you will have to buy a little something extra to bring the cost up to $50 because you need that much to use the code. I think it costs about $43.99 so just add another $7 to it and your good. herbie
Also it might save you a little money by doing this. I bought a Bosch oxygen sensor from advance auto on line, use coupon code trt30, it will give you 30 percent off but you will have to buy a little something extra to bring the cost up to $50 because you need that much to use the code. I think it costs about $43.99 so just add another $7 to it and your good. herbie
07-05-2016, 01:07 PM
#7
Update
Well the same problem came back after the O2 sensor was replaced.
I then replaced spark plugs with motorcraft platinum plugs, replaced the distributor, replaced the ignition control module, and the problem never went away.
I actually fixed the problem on accident. I went to change out the instrument cluster, ( in another post ) and noticed the battery voltage was low. So I checked the battery and it passed with flying colors, so I tested the alternator and it was a little weak but still was working. I put in a rebuilt alternator and charging system came back up where it should be.
Turns out the alternator was weak and causing the spark to be weak at times which triggered the cel light to flash 4 times and the rpms to raise up high then drop off to a stall then back to normal idle. Everything is fine now the cel is gone and normal idle is back.
Solution for my truck---- Alternator
Hope this helps someone,herbie
I then replaced spark plugs with motorcraft platinum plugs, replaced the distributor, replaced the ignition control module, and the problem never went away.
I actually fixed the problem on accident. I went to change out the instrument cluster, ( in another post ) and noticed the battery voltage was low. So I checked the battery and it passed with flying colors, so I tested the alternator and it was a little weak but still was working. I put in a rebuilt alternator and charging system came back up where it should be.
Turns out the alternator was weak and causing the spark to be weak at times which triggered the cel light to flash 4 times and the rpms to raise up high then drop off to a stall then back to normal idle. Everything is fine now the cel is gone and normal idle is back.
Solution for my truck---- Alternator
Hope this helps someone,herbie