Reference Manual

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Chapter 1: Engines: Oldsmobile V8s: Cleaning out the EGR passages

Article by: Jason Adcock

The 307 engine is very sensitive to EGR flow; even a 50% reduction is enough to cause pinging headaches. Your car should run fine on 87 octane fuel. Mine with 50% blockage still pinged on 93 octane, with the timing set a 20 degrees, as factory-specified. Wanna cheap performance boost? Remove the carb, and run a 3/8" drill bit to clean out the EGR passages. Mine picked up a lot of power with that, and I started running 87 octane again, with no pinging. The 307-Y likes EGR. This engine (ECM Program?) is VERY sensitive to EGR.

Remove carb, run a long 3/8" drill bit down the EGR tubes, drill out the carbon. If really bad, remove EGR valve and run a piano wire through the passages. You can remove the EGR tubes and clean them that way as well. You will see the build up.

My 307 ran MUCH better after I cleared the passages. Of all things, EGR to help power! (5)