Armalite

1988 pickup 5sp 22re

When I accelerate the truck will stumble and jerk like it is missfiring and have no power. When it stumbles the cel will flash but it won't store any codes.

previously I had code 25 which is running lean. It would stumble randomly and not very often. I changed the 02 sensor out today and it stumbles every time give it gas unless i really baby it.

The 02 sensor was a bosch. Could it be a bad 02 sensor even though its new?

Any other thoughts on what it could be?

MB4runner

Flashing cel is usually a misfire... So could be distributor, plugs, plug wires, or fuel related anything from o2 sensor to fuel injectors and everything in between.

The only possible way to narrow it does is see what codes are thrown, but you said it doesn't store any which is really strange.

And as far as the o2 sensor is concerned, try unpluggin the harness and see how it drives, it will throw a code for sure, but if it drives normally then the o2 sensor is the problem.

Armalite

Ok so I reinstalled the old 02 sensor and it runs way better. I took the new 02 sensor back to autozone and ordered the direct fit denso.

Why would my cel come on and not store the codes? Every time I checked for codes the cel would just flash over and over with no breaks which means no codes right?

Thanks MB4runner for the reply. I get the 02 sensor on tuesday and hopefully that will take care of the problem.

Armalite

Today I got the denso o2 sensor installed and runs pretty well except for the occasional misfire.

It only happens when I first start driving while the engine is still cold and by cold i mean i let it warm up for a couple minutes. After that it runs fine.

I am going to get a new fuel filter, ngk plugs and wires, and some redline fuel injector cleaner. The computer still isn't storing the codes .

What else should I be checking to fix this problem and does anyone know why it won't store codes?

Armalite

I decided to pick up a couple cans of seafoam and run them through the engine. While I am pouring the 1/3 can into the pcv hose white smoke starts puffing up into my face. Initial thoughts were ( I hate you seafoam what did you do to my engine) but after I looked around I found the leak coming from the axhaust just below the headers.

Well I crawled under the truck and found out i only had 2 out of 3 nuts holding the exhaust on. So I found another nut and put that on there and tightened the other two which were very lose. She purs like a kitten now

No cel and no stumbles. I never noticed it before because when i bought the truck the lower exhaust was held up by wire and it rattled or atleast I thought it did. No more rattly exhaust now either