Too Lean And Too Rich, Runs Rough

[ejs]

1993 SC 300 with 186,000 miles, the check light is on and error codes 25 and 26 indicates it is too lean and too rich. Hoping for the easy solution I changed the oxygen sensors on the exhaust manifold and the fuel filter. Still runs rough. Any other suggestions before I bite the bullet and take it in.

[jzz30]

do you smell raw fuel coming out the exhaust? and is the car driveable?

[fnutz09]

1993 SC 300 with 186,000 miles, the check light is on and error codes 25 and 26 indicates it is too lean and too rich.  Hoping for the easy solution I changed the oxygen sensors on the exhaust manifold and the fuel filter.  Still runs rough.  Any other suggestions before I bite the bullet and take it in.

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Check you Mass Air Flow Sensor by the air intake...You might be able to clean it or just replace it...

[melhadri]

EGR Valve? Check my post: http://us.lexusownersclub.com/forums/index...pic=17088&st=30

[ejs]

Thanks, good news and bad news. I was just relying on the error codes, didn't think that I had a misfire, it runs but runs as if I have a misfire. Checked the wires and now will pull the sparkplugs which is always a chore. Had the plugs replaced 20,000 miles ago. Don't know if they screwed something up. I have a plug that isn't firing for some reason. The oxygen sensors and fuel filter replacement should have been done anyway and I look at that as preventive medicine. I like the car, don't like to work on them anymore. My other car is a 1973 BMW 2002 which keeps me busy enough. Thanks for all posts. This forum is very helpful to me. A 1993 doesn't have a MAS sensor that you can clean, I already took that off and looked.

[mehullica]

Bad plug wires. Check the voltage reading on terminals E1/OX1 and E1/OX2 at 2500rpms. Should be switching up and down. If not check your plug wires.