89 oldsmobile custom cruiser, 307 engine, 225000 with carb. Its not a fuel injection engine hi, recently I've made a modification on the exhaust. I have cut the Y pipe and put a double exhaust, double mufflers. I know you can't do that on a newly car. Mine don't have a sensor on the cat. When I start the engine, a little light of check engine appear and the car run fine but its extremely hard on gas.30$ is nothing! Before it was economical like a V6! Someone told me it was the 02 sensor in the manifold. I've check and I got one. I don't want to replace the Y pipe and everything. Do you have solutions? Thanks alot!
Thursday, November 22nd, 2007 AT 11:14 AM