hey guys, the other morning i went to start my truck and it sounded like it was running on 3 cylinders instead of 4. i drove it home, and let it sit for a while and then it worked good again. well this morning it did the same thing so i opened the hood, and listened to the engine and it sounded fine but then i went and listened to the exhaust and it sounded really bad, like it was running off of 3 cyliners. i also noticed that because it has been about 10-15 degrees at night that my truck bed would frost over and when i warmed my truck up it would stay frosted over, but this morning my bed was actually hot, like the muffler was way over heating. i have 237,000 on the 22re and the exhuast wasnt change for about 150,000. i was wondering if the cat or muffler could be messed up?

bryan

 

How old is the Cat? it could be clogged or partially clogged

 

Does kinda sound like a cat issue... drill a couple 1/2" holes (or cut the pipe) right before the cat and run it... see if that makes a noticeable difference (besided the loudness).... make sure you can weld it back up when your done though.... If you cant take it to a shop, they might be able to help.

 

is there any way that it could just be plugs,wires and maybe cap and rotor? i am gonna take it in this saturday and have the exhuast completly re-done. the cat is probably 5 years old or so. it hasnt been replaced for atleast a good 100,000 miles. i also do have a little crack in my exhuast header

bryan

 

if its runnin on 3 cylinders, or seems like it, it is possible... easy check for wires is to let it run when its pitch black outside and watch the wires... you can see them arcing if the have cuts in them, which would cause it to run in geo mode or worse.... another cool thing is you can sometimes see the spark plugs fire through the ceramic... anyway.... cap and rotor, yank them off and look for corrosion or cracks... also has it been rainy or humid where you live lately when the truck has been runnin in psuedo geo mode?

 

it has been kinda foggy and crappy around here latley, and i have washed my truck and under the hood. i checked the wires, they are still good, i am gonna see what the cap and rotor looks like tonight. i asked one of my auto teachers and they said that since i have a crack in my exhuast manifold that it can cause my O2 sensor to go bad and that will make my truck run all goofy? i was thinking about replacing the whole exhust system and seeing what that would do.

bryan

 

if the O2 was to blame it would throw a check engine light...is the CEL on?

 

Well.... not necessarily, however, with the way your truck is running, I'm REALLY surprised there isn't a check engine light. Maybe the bulb is burned out? Can you get it to an Autozone and get the codes pulled?

Is the split in your exhaust before or after the cat? If before, you could be losing enough temp that the cat never "lights off" and it would plug pretty darn quick...

 

ya i have no check engine light on, but the O2 sensor is before the cat, right on my exhuast manifold. does autozone check codes for free or what?

 

ya AZ checks for free.... get in the truck, turn the key to the on position and see if the check engine light comes on. If it does, the bulb is working....

Bryan what year/model is the vehicle.... I may be able to guide you through pullin the codes yourself, so that you'll know how to in the future.

 

ya it does light up when the key is in the one position, it is a 92 pickup 4x4 22re

 

light is working like normal.... I'll dig up some check info... i bet its goina be a no-code, but its worth a try.

 

thats what i am thinking also, thanks alot for taking the time

bryan

 

Heres the link to the FSM I'm referencing, its for a 93, but they're close enough:

http://personal.utulsa.edu/~nathan-b...fsm/index.html

To pull the engine codes:

http://personal.utulsa.edu/~nathan-b...26diagnosi.pdf

That special service tool they use to connect the two terminals in the connector... paperclip works just the same.

Basically, with the truck at norm. operating temp, and engine not running, pop the hood, pop the cover off the diag. connector shown in the second figure on the first page, insert a paper clip to connect the two terminals like shown, turn the key to the "on" position (dont start it), and watch the CEL for flashes.... the last pages list how the codes are shown by the flashing, and what codes mean what.

Let me know what you find! Your truck will be all better in no time.

 

dont worry bout the time, i started off not knowing a lot, and either taught myself through reading factory service manuals, or asking lots of questions.... we all have to start somewhere, im just glad i can help and show you a few things about your truck.

 

alright, i will do so when i get home after work and tell you what i find. thanks

bryan

 

no prob!

 

under the hood, in front of the fuse box on the passenger side, is a grey box that says "diagnostics" on it. Leave the key off, put a jumper between pins TE1 and E1, turn the key to the "on" position. Note the flashes. If it just flashes continuously then there are no stored codes. If it flashes and pauses and flashes again, note the the flash cycles and post them back up. ie. flash flash, pause pause, flash, pause would be code 21.

 

hey, i went and replaced the cap/rotor on my truck and it seems to help a little bit. also i put 2 bottles of that HEET stuff in my gas tank and my truck didnt act up this morning so that must have helped a little too. i have an appointment for saturday morning at a local exhaust shop and they are going to replace my exhuast manifold so hopefully that will clear things up.

bryan

 

Did you get a chance to check for any stored engine codes? Good to hear a cap and rotor helped. After you get the exhaust work done, post if you have any more problems!