Scottg97

1991 Pick-up 4x4 extra cab SR5 3.0 119K new Head gaskets 5k ago. (almost a year ago)

Here's my problem....In the last month I started getting the cel when the
truck was warming up and wouldn't run that well. But after it was completely
warmed up. If you turn the ignition off and restart the truck it would run beautify and the cel would be off and stays that way as long as the engine is
warm. (if you let it sit for more than a hour it starts all over)

But on really HOT days and with a lot of stopping and starting it has a hard time
maintaining idle.

Ran the codes (21) O2 sensor (52) Knock sensor

Replaced the 02 sensor this morning. Reset the ECU. Still have the same
problems. (code 21 is gone.....still have code 52)

Runs bad warming up (cel on)
Runs great after warm up (cel off)

Is this truly a Knock sensor problem? Or is there something else going on
here. I really don't want to have to tear the top of the engine down if I
dont have too.


Thanks
Scott

myyota

What brand of 02 sensor did you buy ?. I hope it was a Denso 02 sensor, because Bosch 02 sensors don`t work well in toyota`s.

Scottg97

@Myyota........Yep, unfortunately I bought the universal Bosch. Already cut a spliced it in.
But like I said....the 21 code was removed.

@ razed..........I will give that a try. I didn't run it to much yesterday. I went to check the spark plugs to see if I'm running rich. But the plug wire fell apart when I pulled it. So
I'll be replacing them this morning.

tried4x2signN

OEMOEMOEMOEMOEMOEMOEM



I've never had this problem, or owned a truck long enough to put a O2 sensor in it, but I can tell you one thing. When that time comes it'll be an OEM part.

Same as any other wear part I might put on my truck.

250000_yota

He's 100% right about this. I saw alot of older OBD1 (95 and older) cars and trucks come into the dealership that said, "i just replaced _______, and now it runs like crap!" I've replaced many sets of spark plugs, plug wires, o2 sensors, fuel filters, water pumps, timing belts and the such that came from autozone, checker and what have you. I only use Toyota OEM parts.

I even got bit by the Bosch bug once in college. 1 week and two o2 sensors later, I was at the dealership begging for a stock Denso...

Scottg97

O.K. Put a Denso o2 sensor in. Running better, but not great.

Still getting code 52.

Still runs bad during warm up....CEL light on
After it warms up CEL off......Runs great.

once again......Is this truly a Knock sensor problem? Or is there something else going on
here. I really don't want to have to tear the top of the engine down if I
dont have too.