corvettelvr73

Ok I got a check engine light a week ago and i checked the codes 25 and 26 which 25 is running lean and 26 is running rich. I reset the computer and now 700+ miles later the light has come on again with the same 2 codes. I have changed the oxygen sensor at 97,000 miles so that shouldnt be the prob. WHat should i check next??? AFM???

Babypig

I'm gonna say check the O2 sensor first. Then move on to the AFM.

drkgypsy

You get the 26 code immediatly after the 25 code.....mmmm loose ground/wires somewhere????

corvettelvr73

I reset the ECU and now today about 30 miles of driving it came on again and now it is only show a code 25. So I think that it shouldnt be the oxygen sensor but i dont know what else to check. Maybe the AFM needs adjustment. What should I do next? I refuse to take it to a shop untill it starts not running and im stumped like i am now.

drkgypsy

I would check oxygen sensor plug itself. maybe a bit of dirt or something got inside, or the connection might have come loose. When I get home, I'll look at my FSM and see what it says.....I'll post agian tonight, or first thing in the morning.Sorry I can't help more....

drkgypsy

Does your rig backfire w/this lean air/fuel mix? Ok, ya already checked all the hoses and they're connected where they are suppose to be,right? Check all PCV hoses (PCV too if ya want)then check the EGR system. Check to see if the EGR vale stays open(replace if does)check the timing yet agian.
Check the cold start injector time switch,and the cold start injector.( I replaced both injector and switch, $145 rom the stealership,and took less than 10 min.
Then check the fuel pump,fuel filter and the pressure regulator
Check injectors,maybe they're clogged
and lastly: wiring connection,power to ECU(fusible link&main relay),airlow meter,water temp sensor,air temp sensor,throttle position sensor,injection signal(injector wiring,ECU,fuel cut signal)oxygen sensor.<---taken striaght from the FSM....
T

corvettelvr73

That sounds like alot of work. LOL
No It has never backfired and isnt getting bad gas mileage. Im going to check all the hoses to see if any came loose. The fuel filter is new i changed it at around 100K. The pcv valve is too hard to get to not even going to worry with it. Maybe it is something to do with it being much colder outside where I live now. The mornings are frosting now maybe it is something with a loose wire I am going to check around. Ill be sure to keep you posted. Thanks with all the help. I really need a FSM. Where did you get yours?

drkgypsy

First off, check the cold start inj, and cold start inj time switch (since you said the temps are fallen). And second, you are welcome sir....and I bought my FSM rom Hamer Toyota.....close to $300 for the 2 vol set.
Please do keep me posted, and any question, anytime....pm, email or im

ATP4984

I had those two codes once, needed an exhaust valve adjustment on cylinder 3.

drkgypsy

both at the same time??

corvettelvr73

Well I havent seen the check engine light since the last time a week or so ago. For some reason this past week it same been warm outside and not frosting in the morining. It probably is the cold start sensor. I have checked the AFM and I tried to check the cold start sensor but it is hard to get to and when I think about it the engine is too hot. I will keep you posted on it drkgypsy if I see the light any time soon. Thanks

callmej75

Is it hard to start on the cold mornings? If so it would be either the cold start sensor or injector. One way to check the injector is pull the plug and OHM it out and see if that checks out.

corvettelvr73

It isnt hard to start on cold mornings not that I have noticed but usually I remote start it while im eating breakfast so it will be all toasty when im ready to go. Im going to check a few more things if that light comes back on.

callmej75

wouldn't point to the cold start injector then....mine would crank for about 6-8 seconds before it would start when my time switch went out. Might just be an O2....if it runs good and gets as good as expected gas mileage then i would just go with it! these things are so delicate....

Joe Otis

I've had both those codes too recently that come and go. Just found this morning that the TVV (Thermal Vacuum Valve) at the top rear of the engine had the vacuum tubes disconnected. The tubes attach to the valve which is plastic and the prongs became brittle and broke off. One tube goes to your intake and the other comes from your charcoal cannister. I just jerry rigged the vacuum tubes back on with some smaller plastic fittings that I had laying around and drove around and the CEL cleared itself. So far so good!

good luck, that TVV is a pain to get at see!

joe

callmej75

Glad to see you caught it. I know the one you're talking about....I changed out all my vacuum lines once and it was a pain to get to! Kinda gotta feel it out and I got frankenstein knuckles so it was a PITA!

Amir904

i just went to autozone today, got a p0133 code for my check engine light, dude says its the O2 sensor, and this is 1000 miles after i did the seafoaming.

drkgypsy

did you do the seafoam treatment before or after you replaced your 02 sensor?

Amir904

i did the seafoam before my O2 sensors went bad. i have not replaced it yet. some say seafoaming ruins the O2 sensors.