Bugzman

I hate to post one of these because normally my FSM solves all my issues but this time i'm stumped, just looking for somethings to try before I go crazy and starting taking the intake manifold and head off.

to start off this is what the trucks got.
85' 22re 60k on a rebuild.
trail gear header
trail gear intake.
full 2.25 exhaust
running 35's with 5.29s


I have been getting a check engine light when ever im under a light load, about 1/4 to half throttle, between 2k and 3k RPM, at low speed. the code is number 5 for the O2 sensor.

I replaced the O2 sensor about 5 months ago just cause and the code is still coming. I followed the FSM steps for testing the o2 sensor but I cant seem the thing to do anything. after tons of reading on here I read that because of my header my sensor might be to far down the line ( about halfway between the cat and the headers end. ) and in turn is not getting hot enough. but for all i know i'm not testing the sensor right. (running the single wire o2 sensor.)

i did some test to see if maybe the code was from running rich or lean but I don't know how to tell which. I did have a smog check recently and my Hydrocarbons were high, I replaced the cat and the dropped down a lot but i feel as if i put a band aid on a bigger issue.

when compared to a friends stock 89 with a 22re, my motor shakes like crazy at 850 rpm, and then smooths out around 950. where the 89's just purrs, I also noticed that i have a bit of on uneven exhaust flow, almost like a pop every .7 seconds at idle.

are the idle and the engine code connected? what should i replace or check? i'm dropping a new trans in as we speak so money is tight. I don't want to replace something like the ECU if its not necessary.

im going to go through the truck vacuum system line by line and check for leaks but I have no clue what to check from here. sorry for the essay. and thanks for the help.

Kristo44

I am having the same issue with my 88 22re. rough idle and code 5 with a 4 wire Ox sensor that was replaced about 3000miles ago (Denso). thanks.

58rennur4

iTrader: (1)

Stupid question did you reset EFI fuse after replacing O2 sensor?

Bugzman

yes, many times. my best guess is that under mild load the o2 sensor is not getting hot enough due to my header, causing the light. I think my rough idle is just leaky or old injectors. 290k on the injectors. one day ill pull the head and clean or replace anything that looks bad.

58rennur4

iTrader: (1)

I think you need practice before starting yours! Come over and do mine first

58rennur4

iTrader: (1)

ANy luck finding out issue? IACV, Cold Start Switch, or TSU to computer?

technojunkie

did you check the wiring between the O2 and ECU? These trucks are getting pretty old, it's not unreasonable to think a wire might be broken or failing.

osv

that's one of the reasons why i haven't yet put that header on my rig... i think that the later model 22re's have heated o2 sensors, i was wondering if it would be possible to plug the hot wire directly into 12v somehow, and run those later o2 sensors on our old rigs.

if there is a slight vacuum present on the egr at idle, it could be bleeding exhaust into the intake manifold, which might account for the rough idle... you could unplug the vacuum line from the top of the egr, and see if it makes a difference in the idle.