fuel comsumption

[d3ad1ysp0rk]

Saturnspeed is right. I have a 99SL2 as well, and after replacing the ECTS a while ago, it now runs a little above 1/4th while DRIVING and close to 1/2 when stopped (unless it's really cold out). The fan will kick in when it gets close to the 3/4ths spot and bring it down near 1/2 again.

[nightbird]

I have replaced my cat twice and never got a warning, had to guess. The first time the muffler guy said it wasn't highly clogged, however replacing it made a huge improvement. The engine ran hotter when it was clogged, and in one case, backfired. I called the Saturn 800 number and they said a catalytic converter has a life of 70,000 miles. Engine runs slightly cooler, and a lot better when this is replaced.

On my 150,000 mile 94 SL1, replacing the idler pulley made a real performance increase, and recently replacing an ignition coil made a huge performance difference and cleaner oil too.

[whoareyou4]

I have a 97 SC2 with the same problem, I've only lost 60 mile per tankful at this point. Chamging the Plugs and wires are a good thing to do, at least check your plugs. Mine were in very poor shape and I had alot of arcing between the boots down at the coil packs.

The down side is that, replacing all that stuff did not improve my mileage one bit.

My next items to attack are the O2 sensor (in the exhaust manifold), and the coolant temp sensor.

I had a good O2 sensor laying around and I replaced that, but that did no good either. So today I plan to replace the coolant temp sensor and try that.

I will let you know what that does.

[rajjhauf]

I just changed my daughters ects and it made no change on the temp. gauge, it still runs at or below the 1/4 mark. I bought a new termostat and that was the problem. Now it runs at the 1/2 mark. Thanks to everyone.