mwd Posted July 8, 2005 Share Posted July 8, 2005 The Haynes manual says the MAP (manifold absolute pressure?) sensor should output "below 3 volts at idle (high vacuum) to 2 volts with wide open throttle (WOT) (low vacuum)". I have a 96 Outback 2.2L. Are these voltage specs correct? I am concerned that the Haynes manual may not be correct for my particular year/engine. My MAP sensor output is 1.5 V at idle and it drops to 1.4 V at ~4000 RPM. Symptoms: hesitation between 2-3000 RPM. I have added teflon washers under the knock sensor to keep the ECM from giving a code for the knock sensor. I suspect that the O2 sensor is original-- 115,000 miles. Is it for sure that the MAP sensor is bad? It is $180 from 1stSubaruParts.com. Any better price available elsewhere? Or is replacing the knock sensor or O2 sensor a better bet? Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted July 8, 2005 Share Posted July 8, 2005 The teflon washer thing really doesn't work. I tried it, it made no difference, and the bolt actually came loose, creating more issues. 115k on the orig O2 sensor.....it's probably time to be replaced. Check out https://www.subarugenuineparts.com/oe_parts_cat.html Quote Link to comment Share on other sites More sharing options...
mwd Posted July 8, 2005 Author Share Posted July 8, 2005 The teflon washer thing really doesn't work. I tried it, it made no difference, and the bolt actually came loose, creating more issues. 115k on the orig O2 sensor.....it's probably time to be replaced. Check out https://www.subarugenuineparts.com/oe_parts_cat.html I used Gylon washers (low cold flow form of teflon gasket material) and used thread locker on the bolt. Also torqued it to 16 ft-lbs. Seems to be holding so far. When you say it doesn't work, do you mean that it doesn't stay tight enough or that it still throws a code or that the hesitation is still there due to the knock sensor retarding the timing? My hesitation is still there but is much better with the 2 gylon washers. Thanks for the reply. Mike (BSME '76) Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted July 9, 2005 Share Posted July 9, 2005 I did not notice a difference in reduction of hesitation with the washers. This was before it came loose. So I just removed them. The "hesitation" I was experiencing was related to the automatic transmission. Once I did my swap, I didn't have any hesitation issues. Quote Link to comment Share on other sites More sharing options...
mwd Posted July 13, 2005 Author Share Posted July 13, 2005 Anybody got any reliable specs on the MAP sensor voltages? Quote Link to comment Share on other sites More sharing options...
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