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Hey guys,

My 01 Tahoe is showing a "Check Engine" light.
I remember on some other GM stuff, you could put a paperclip across two pins in the under-the dash receptical and count the blinks. One long one was a 10 and short ones were ones.

Is this still the case and where would this receptical be located in the Tahoe? and just how do you go about it?

Thanks a million for all the past help.
 

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I've never been a huge fan of doing that. Have you asked a local shop like Napa or whatever to take a reading? IMO I would just get it read right so theres no mistake. More accurate anyway.

Then post back so we can help. Is there something obvious wrong so far?
 

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Nothing appears to be going wrong at this point, however, I thought I might have got a smell of rotten gas exhust but not sure it was coming from my Ho.
 

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Rotten egg smell is usually catalitic converter problem. If its choking motor it might throw an SES
 

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Jumpering pins to get the CEL to flash out trouble codes is the old OBD-1 method. 1996 and up are OBD-2. You have to have an OBD2 scanner/code reader to get codes on your Tahoe. Some parts stores will pull trouble codes for free in the hopes of selling something. I even think Autozone includes a coder reader in their loan a tool thing.
If you want to DIY, I've seen OBD-2 code readers for as little as $50 on up to whatever you want to pay.
When pulling codes, remember that a trouble code by itself does not constitute a thorough diagnosis. A trouble code tells you where to begin the diagnosis.
 

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Smells like trouble

Rotten egg smell is being caused by raw fuel burning in the catalytic converter. A little odor at startup or at idle is OK, but otherwise not good for the converter and usually sign of trouble upstream of the cat.

From: aa1car

One thing temperature measurements will tell you, however, is if the converter is working too hard. An infrared noncontact pyrometer or a temperature probe will tell you if the converter is running unusually or dangerously hot. If the converter outlet temperature is 200 or more degrees higher then the inlet temperature, it means the engine is running rich and there's a lot of CO in the exhaust that needs to be burned. A rich fuel mixture will often produce a "rotten egg" odor in the exhaust (the smell is hydrogen sulfide). Underlying problems may include an engine management system that is not going into closed loop (check the coolant and oxygen sensors, or for a thermostat stick in the open position), plugged PCV valve, or excessive fuel pressure (bad fuel regulator). High CO levels in the exhaust can also be caused by an inoperative air pump system.
 
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Rotten egg smell is being caused by raw fuel burning in the catalytic converter. A little odor at startup or at idle is OK, but otherwise not good for the converter and usually sign of trouble upstream of the cat.

From: aa1car

One thing temperature measurements will tell you, however, is if the converter is working too hard. An infrared noncontact pyrometer or a temperature probe will tell you if the converter is running unusually or dangerously hot. If the converter outlet temperature is 200 or more degrees higher then the inlet temperature, it means the engine is running rich and there's a lot of CO in the exhaust that needs to be burned. A rich fuel mixture will often produce a "rotten egg" odor in the exhaust (the smell is hydrogen sulfide). Underlying problems may include an engine management system that is not going into closed loop (check the coolant and oxygen sensors, or for a thermostat stick in the open position), plugged PCV valve, or excessive fuel pressure (bad fuel regulator). High CO levels in the exhaust can also be caused by an inoperative air pump system.
Nice explanation...Your my daddy!
 

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How about the software for laptops? Anyone here use it? I know its out there somewhere. Im sure most are more than i want to pay though.....but i know theres gotta be someone on here that uses it :great:
 

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How about the software for laptops? Anyone here use it? I know its out there somewhere. Im sure most are more than i want to pay though.....but i know theres gotta be someone on here that uses it :great:
People on my Fiero forum have been doing that for a while, you need an adapter plug to go from the OBD plug then to a USB plug in your lap top.

Then a program to read the codes. Not sure what the guys have been using for the program, I can try and find the thread if you are really interested.
 

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Check out CarChip from DAVIS Instruments in California. Adapter, software and cables included.
Keith
 
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