[ddarkslayer]

so the threads I've made the past couple of weeks of my motor running rich and Idle surges. The idle surges where because I forgot to plug the MAF back in when I changed the sample tube and I went under my car today to inspect the 02 sensors I pulled them out and noticed that there was nothing but carbon deposit built up in volume on both of them and I shake the driverside o2 sensor and I can hear this rattling. So I'm assuming its gone bad But I'm not for sure tho. I used the kitchen stove to warm up the sensor while I used a multimeter to see if there where any changes in voltage or resistants. it didn't show any voltage and the resistance kept jumping all over the place. so I'm not sure if I've done it right. What do you guys think?

[black89GT]

How does it run from a cold start? Start right up and run fine or idle ruff/like shit tills its warm then get better?

[ddarkslayer]

Originally Posted by black89GT How does it run from a cold start? Start right up and run fine or idle ruff/like shit tills its warm then get better?

when I start it up it runs fine for a couple of seconds and then the check engine light comes on. and the rpm drops

[black89GT]

Originally Posted by ddarkslayer when I start it up it runs fine for a couple of seconds and then the check engine light comes on. and the rpm drops

Did you pull codes? But id say its the o2's. I know my truck needs them and it wont idle cold with out me holding the gas a bit. Then it surges also. I dont knwo the symptoms of a stang with bad o2's cause I havent had to deal with them yet. Altho my fox does have idle surge problems.. Ill be changing out somethings this spring tho.

[ddarkslayer]

its code 92 a rich code

[black89GT]

Well if they are bad it sends the wrong signal, so it dont know how much fuel to give right?

[ddarkslayer]

well this is my theory. I put stabilizer in the tank and ran half the amount of fuel that you normally have to run it with so I'm running a higher concentrate of fuel stabalizer so the stabalizer is cleaning up the carbon deposit all in the inside of the motor and contaminating the O2 sensors. thats just my theory but I don't know if that would make sense or not

[black89GT]

Idk, Was it acting like this before you added the stable

[ddarkslayer]

no it started acting like that when I installed the 255 fuel pump but the stablizer went in first.

[black89GT]

Hrmm... Hope someone with better knowledge chimes in I guess. If it was me i would change the O2's

[ddarkslayer]

haha yea thats what I'm going to do first thing tomorrow Cuz I got 164k on the motor and they are the original o2 sensors

[black89GT]

Originally Posted by ddarkslayer haha yea thats what I'm going to do first thing tomorrow Cuz I got 164k on the motor and they are the original o2 sensors

yeah do that!!

[ddarkslayer]

so I just changed the 02s and it still running rich. crap my next theory is the 24 Ibs. injectors It doesn't make sense because my car use to run fine with them in then when I changed the fuel pump to a 255 then it starts running rich

[ddarkslayer]

now I just drove around the block and I have a slight exhaust leak and so when I floor it I get smoke building up in my interior I have a broken main harnest grommet to

[black89GT]

How is your maf? Try cleaning it out maybe its getting a bad reading?

[ddarkslayer]

I tested the resistance on every pin and it checked out okay I plugged it in and it doesn't surge anymore so the MAF is good dang I've ran out of Ideas

[ddarkslayer]

What if I buy an ajustable fuel pressure regulator would that help or would that just be a bandaid to hide the real problem

[flattusmaximus78]

Ehh I don't think so. If you read it via a wide band no matter how rich or lean you adjust an adjustable fpr its only making adjustments at wide open. The computer will always adjust the air fuels once you have made adjustments.