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Help with code PO134

05-09-2005, 08:28 AM
Hi guys
I bought a code reader on sale. Maybe a mistake....
I guess my "check engine" lamp may be burned out, I don't see where it should be. (I bought the van used, no owners manual)
It's a '97 Astro
I get a Code PO134, which 1 manual translates as an O2 sensor fault. The manual with the reader states "O2 Sensor circuit, No Activity Detected (Bank 1 Sensor 1)"
Which means what?
I looked under the van, and found a sensor in each exhaust bank,(heated i think, 4 wires) another before the Cat, (2 wires) and another after the Cat, (2 wires)
The wires look good. The sensors looked seized. I see very little room...
The book also lists bank 2, and sensor 2 and 3, and some other O2 numbers, with different codes, which I don't get readings for.
Any help would be appreciated, as I've never done one of these, and I'm told there's some tricks.

05-09-2005, 10:13 PM
Checked my Haynes manual for the PO134 which says O2 sensor voltage high. The O2 sensors fluctuate between high and low voltage in normal operation (we're not talking much voltage here). If it is stuck in a high voltage reading it's fried. The O2 sensors can fail electrically or just get clogged. I've seen posts about potentially cleaning one, but I don't think it's really possible. Check the wires and connections first. These sensors are exposed to a lot of dirt and water from the road. The '97 has 4 of these things. has testing information for O2 sensors. You'll need a digital mulimeter, which you can get for around twenty bucks. Got mine at home depot of all places. Now I am no expert at using this by any means, it's new territory for me persanally, but if you've seen my other post I'd just as soon not buy another TPS if I don't have to.
The O2 sensors for the '97 look like they run $45 to around $80 for the '97, so you've got a good excuse for a twenty dollar tool. The testing information on the autozone web page talks about back probing, which I finally found out means sticking a straight pin into the back end of the connector where the wires are attached to connect the lead off the meter. I didn't have a straight pin, so I used a stiff piece of uninsulated wire. The goal is to create a contact point with the sensor in place and the wiring connected.
As far as removing and installing an O2 sensor, I've seen something called an O2 sensor socket, however, I've replaced a couple with nothing more than an adjustable wrench. One pointer that I've run across is avoid dropping the sensor on the drive way. (sounds like good advice for any sensor, although I've done that too)

05-09-2005, 11:23 PM
ok, saw your other post, on my thread no less, see you have the digital mulimeter, and pointers on using lamps to test for shorts. pointers on how to use my new 20 dollar tool would be greatly appreciated.

05-10-2005, 08:19 AM
Hmm. My Haynes manual just said O2 sensor fault.
I'll go to Autozone at lunch and check that. Thanks
I phoned GM, the "sensor 1" is ahead of the cat.
The "bank 1" they think means passenger side.
In Canada, GM wants $167 for the sensor, best price I've found is $75.
Digital meter: any specific questions? or just general?
I'll write up something for you at lunch

05-11-2006, 09:37 PM
Ok guys I also have this same problem and my scanner says something about a Global Good Trip, Freeze Frame and Hex Code.. anyone knowz what that is?

05-12-2006, 07:41 AM
I haven't seen anything like what you're seeing....
However, for my code, the GM tech was wrong. "Sensor 1" is closest to the engine, "Bank 1" is the bank with cylinder #1 on it. (drivers side)

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