You need a scanning device to read the codes, you could purchase one or drive the vehicle to your local auto parts store and they will read the codes for you for zip.
wiil a 1999 blazer engine fit a 2002 blazer
No.
The computer has detected a fault with the emissions controls. Have the computer scanned and this will help to find the defective part or parts.
No.
Dex-cool
Yes. They used the exact same engine.
The thermostat in the 2002 Blazer will most likely be in the top radiator hose engine inlet, depending on the engine in the vehicle. The top hose is removed then the inlet unbolted to reach the thermostat.
clogged cat
I have a 2002 Blazer with the 4.3L engine and 3.73 differential gear ratio, it gives me 17 mpg on average.
I have a 2002 Blazer with the 4.3L engine and it gets 17 to 19 MPG, average.
Is this a Tralblazer with a 4.2L engine. Your vehicle may not be so equipped. If that is the case, factory service information recommends draining the radiator by disconnecting the lower radiator hose.
Assuming that it has a 4.3L engine, it would be the distributor.