SES Light on GMC Sierra 1500

Went to have safety inspection on my truck done and was told it would
not pass do to the service-engine-soon light being on. Took the
vehicle to a gmc dealer and was told that the cat. converter needed to
be replaced. My truck is a 2000 model and has 101k on it. The dealer
charged 90.00 to tell me this and quoted close to 1200.00 to put a new
converter on.

First of all I found out not to take a vehicle to the dealer for this,
Autozone and others will tell you the same information for free. Of
course I did not have the converter replaced for the price that was
quoted. My reaction was what the heck are they smoking. I picked up
the vehicle and with no choice paid the 90.00 fee.

On a 2000 model there are two cataletic converters, so the next day I
called the dealer that quoted 1200.00 for the repair and asked
specifically which converter was diagnosed bad. I was told that it was
the one on the passanger side.

So off to autozone I went. Autozone can order a direct boltup
replacement for about 320.00 dollars. They also have a universal for
about 105.00 dollars.(Just one) So I purchased a universal.(In Stock)
I then took the part to a muffler shop that would install the new
part, I was quoted 50.00 to remove and replace with my supplied new
converter.

When I arrived at the muffler shop, I was asked to show him the new
part. I did and found out that the universal part that I purchased
from autozone would not work due to the oval shape and on a 2000 model
the converter is round.

The muffler shop carried the correct shape converter manufactured by
magnaflow. I purchased the converter and had them install it. This
cost was 175.00 out the door. Took about 30 min.
The next morning I went back to autozone and returned the converter
that was the wrong shape and had the codes cleared from my truck.
Initially I disconnected the battery cables overnight... This does not
work...

I then drove the my truck for 60 miles to see if the SES light was
going to come back on, it did not come back on so I had the safety
inspection done. My truck Passed....

I had alot of people tell me to replace the co2 sensors first, that
alot of the time this is the problem and to go the cheapest route
first. There are four sensors on this truck. The computer codes will
correctly tell you which part is not performing. Just do not go to a
dealer that has crack on the lunch menu and try to charge 1200.00 for
a 175.00 Fix.

Also I have been told there is a fedral Emissions law that requires
the manufacturer to warranty emissions failures for the first 100000
miles. I did not check into it because naturally my truck was at
101000 miles.

Hope this helps anyone who does not want to pay 1200.00 to a crook
dealer.