RE: Bad gas mileage on on 03 blazer
Sea foam will do the trick. Is the motor throwing a code, usually a bad O2 sensor will give you ****ty gas milage. But for sea foam through the intake.
[ol][*]Park car in a well-ventilated area.[*]Start car and run until it reaches closed loop (generally 5-10 minutes, and above 160°).[*]Open hood.[*]Find black hose that runs from the middle of the driver's side of the intake manifold into the black box on the firewall. This is the brake booster hose.[*]Remove the hose end from the black box; you'll hear the vacuum and the car's idle change.
[ul][*]If your car stalls out, then use the middle hose that attaches to the passenger side of the throttle body. It's an L-shaped piece of hose, that connects to a black box mounted on the pass. side of the intake manifold. Pull the end connected to that box, and use that for sucking the liquid in, detailed below. [/ul][*]
Place end of hose into the top of the Carbon Cleaner bottle. Allow it to suck liquid out until the engine starts to idle noticeably lower; then remove the hose from the bottle. Do not pour enough to stall the engine yet.
[ul][*]Warning: Sea Foam does not recommend sticking a vacuum line into the bottle, but rather pouring the liquid into the line by using your thumb over the top of the bottle to regulate the flow. This prevents too much liquid from being drawn in and possible hydro-locking. It is your choice how to do it, at your own risk. [/ul][*]Repeat the above until between 1/3 and 1/2 of the liquid has been used.[*]Now let enough of the liquid be sucked in until it stalls the engine.[*]Turn off ignition.[*]Replace black hose end into brake master cylinder (the black box on the firewall).
[ul][*]If you used the throttle body connection, reconnect it back to the black box. [/ul][/ol]
For the throttle body, Take off the snorkel for the intake (while the car is off). You'll have a center nut on top of the throttle body. Take it off and then pull the back of the "hat" foward and up. Once that is out, use some throttle body cleaner and spray it on the bore and the throttle plate. Have someone or something hold down the gas pedal so you can get down behind the plate. Use a rag and a soft brush to losen the carbon and to extract it. IT WILL BE DIFFICULT TO START. Just crank it 10 seconds at a time and give it a little gas to get more oxygen in. Once it is started let it run till it stops smoking real bad. Then drive it to get all the lose carbon blown out.