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Problems with EGR Valve and O2 Sensor - Bank 1/Sensor 1


automotivetoys
01-03-2009, 11:41 PM
I have a 1996 Chevrolet Tahoe with a 5.7 V8 engine. Tonight on my way home my service engine soon light came on. I immediately stopped at Auto Zone and my truck was throwing two codes. 1st code was P1406 (Incorrect EGR valve pintle position) 2nd code was P0135 (Circuit Failure in heated oxygen sensor bank 1 sensor 1)

I have already removed my EGR valve and the pintle was easy to push in and our however it did stick a few times while closing. I sprayed some intake cleaner into a bowl and submerged 3/4 of an inch of the valve in the fluid to loosen things up and remove all the gunk that has built up over the years. I am going to let it sit overnight and will reinstall it tomorrow along with a new gasket. I am aware of a GM software update that will allow a higher tolerance than 10% of the pintle position but I haven't gotten around to taking it to the dealer.

My main question is what is the deal with the O2 sensor code? I can't find much info. on this particular code. I don't even know where to look for this sensor. Can someone explain to me where I can find it and how to start troubleshooting what the problem is!?

tempfixit
01-04-2009, 03:27 AM
I have a 1996 Chevrolet Tahoe with a 5.7 V8 engine. Tonight on my way home my service engine soon light came on. I immediately stopped at Auto Zone and my truck was throwing two codes. 1st code was P1406 (Incorrect EGR valve pintle position) 2nd code was P0135 (Circuit Failure in heated oxygen sensor bank 1 sensor 1)

I have already removed my EGR valve and the pintle was easy to push in and our however it did stick a few times while closing. I sprayed some intake cleaner into a bowl and submerged 3/4 of an inch of the valve in the fluid to loosen things up and remove all the gunk that has built up over the years. I am going to let it sit overnight and will reinstall it tomorrow along with a new gasket. I am aware of a GM software update that will allow a higher tolerance than 10% of the pintle position but I haven't gotten around to taking it to the dealer.

My main question is what is the deal with the O2 sensor code? I can't find much info. on this particular code. I don't even know where to look for this sensor. Can someone explain to me where I can find it and how to start troubleshooting what the problem is!?


P0135 Code - Oxygen Sensor is located on the exhaust pipe before the catalytic convertor on the drive side of vehicle. Bank 1 Sensor 1 means Drivers side (Bank One) Sensor 1 means upstream sensor.

Check for broken wires on the sensor.

Do a search and you should find numerous thread on problem.

automotivetoys
01-04-2009, 11:40 AM
I have already done a search and there is very little useful information on this SPECIFIC code. I am well aware that the O2 sensor for bank 1 is located upstream of the cat however I don't know EXACTLY where. I also searched the forum for the location of the oxygen sensor and most replies involved unhelpful vague responses. I'm sorry if I offended you by posting a new thread. Now to the rest of you maybe someone can help me out. I have searched all over my manifolds and the only thing I can find that looks even remotely like an oxygen sensor is screwed into the block just above the exhaust manifold on the drivers side. There is a single black wire sealed and connected to the device that runs up to the top of the engine and connects to something else via a connector. Could this be the correct O2 sensor? Thanks in advance!

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tempfixit
01-04-2009, 01:26 PM
No offense taken. Sorry I did not explain better.

Here is a link that show compotent location:

http://www.autozone.com/az/cds/en_us/0900823d/80/08/70/d8/0900823d800870d8/repairInfoPages.htm

scroll down page to the 96 5.7 picture and it will give you a idea where it is located.

You need to raise the vehicle and support with jack stands and crawl underneath vehicle. The 02 sensor is located on the exhaust pipe which is bolted to the exhaust manifolds.

According to my Factory manual for c/k there are 14 steps to check for fault.

A multimeter is helpful in this diagnose.

First off I would check the fuse for the sensor to make sure it is good. Then check the connector for the sensor and the circuit harness for any bad wires, connector pins,. Check the wires of the sensor.

If you wish me to send you a copy of diagnose steps in manual PM me your email address and I will get them to you.

Also go to autozone.com and look oxygen sensor for your vehicle and it will show a picture of sensor.

Hope this helps

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