MarkN Posted August 11, 2021 Share Posted August 11, 2021 Interesting lesson: Bought my ‘91 two months ago with 56K miles and it seemed sluggish on acceleration. Gas mileage also averaged 21mpg on the highway. So I changed the O2 sensor, plugs, and cleaned the MAF sensor. Not much improvement. I occasionally had a CEL light come in momentarily, and the computer reported a stored “knock sensor” fault (I think E032 but can’t be sure). Anyway, I replaced the sensor this past weekend and the engine had noticeably more power. Filled the tank to perform a mileage check for 225 or so miles. MPG increased to about 27. So, a $38 sensor resulted in a 20% increase in fuel mileage along with better driveability. Nice! 3 1 Link to comment Share on other sites More sharing options...
Padgett Posted August 12, 2021 Share Posted August 12, 2021 (edited) Knock sender can cause a retarded spark. Counts are in ED17. A few at startup or accelerating from a stop are normal but should stop incrementing. Edited August 12, 2021 by Padgett Link to comment Share on other sites More sharing options...
Ron Walker Posted August 13, 2021 Share Posted August 13, 2021 Curious. I was checking the diagnostics, and with battery only (engine not running), my E17 reading was "0." However, with engine running, the E17 reading was 218. Does this sound good or bad or normal? Link to comment Share on other sites More sharing options...
Padgett Posted August 13, 2021 Share Posted August 13, 2021 Normal - all probably on startup but just idling it should not be changing. 1 Link to comment Share on other sites More sharing options...
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