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91 2.5 Chugging and codes

My 91 2.5 E started out chugging as you slowed down in each gear. Now it's missing badly.

It throws (and throws, and throws) a Code 25 (MAT sensor) that even a Chevy mechanic says is rare.

Changed the MAT sensor, checked the voltage on the wire, replaced O2S, MAP sensor, plugs (Rapidfire), cap, rotor, wires, EGR (2 weeks) fuel filter (month ago) and coil. And, it's worse than it was a week ago.

It started after I refilled from almost empty. I've since put in two tanks --one was 94 octane, can of heet, and run Seafoam through the TBI.

Anyone been through this code and solved it?

Any ideas what's going on here?

Reply to
91blues
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Try this...............I bet she's shorted to ground somewhere between the sensor and the ECM.

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Doc

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Reply to
"Doc"

That article is wrong though. Higher resistance = lower voltage Lower resistance = higher voltage Don't you dare try to tell me different - it aintagunna happen.

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~KJ~

Reply to
KJ

The article is not wrong, look again at the scematic, look at where and -how- the ECM is monitoring the voltage (ckt 472).

Reply to
Neil Nelson

Okay, didn't look into the schematic just breezed over the words.

Reply to
KJ

I didn't have to tell you different, you figured it out all by yourself . A little hint:

"Okay, didn't look into the schematic just breezed over the words."

~KJ~ /retards-R-me

Before trying to contradict someone with decades more experience than you, look at the goddamned schematic. You might just save yourself a few humbling moments in future endeavors.

Doc

Reply to
"Doc"

I dun(nt) think you made the schem, that maybe you had just found it in a hurry to post it and help him out. I've done that plenty of times.... so I just thought I was being helpful.

~KJ~

Reply to
KJ

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