Need ECU for my evo x gt35r
Nov 23, 2009, 10:17 AM
#16
Yeah, I'm wondering about this too, what prompted the conclusion that the MAF and MAP were dead? Did he follow the tests prescribed in the service manual to determine this or was it based on P1235/P1238.. codes popping up for "MAF sensor plausibility"... ?
Nov 23, 2009, 10:15 PM
#17
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yes also the o2 ...yah based on p1235/1238
Last edited by UAE_EVOX; Nov 23, 2009 at 11:00 PM.
Nov 23, 2009, 11:46 PM
#18
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The stock MAP is a 3-bar sensor (44.1 psi) so when you subtract out barometric pressure (44.1 - 14.7 = 29.4 psi) you're left with room for another ~29psi before the sensor is maxed out.
However the barometric in Denver is ~12.5 psi so the OP should have room for ~31 psi of boost.
However the barometric in Denver is ~12.5 psi so the OP should have room for ~31 psi of boost.
Nov 24, 2009, 03:25 PM
#19
@UAE_EVOX
Who replaced the MAP and O2 sensors for you? Dealership? Harvey? Do you still have the *old* sensors? If they were replaced based solely on P1235/P1238 codes then you may just replaced perfectly good sensors.
Get in touch with DG Motors/GST Motorsports/HBSpeed..., they spend a lot of time on here helping people with tuning issues and should be able to help you out as well.
Here's a thread that will be of some use: https://www.evolutionm.net/forums/ev...p1238-etc.html
You're right, the nominal rating of the sensor is 3-bar, but if you consider that its a 5V sensor calibrated to read 45.6psi (3.1 bar) at 4.6V, that means if you could actually max out the sensor you could go as high 49.6psi (3.37 bar.) I'm not sure if that qualifies it as 3.5 bar sensor or somewhere in between, but the sensor isn't necessarily accurate the closer you get to its 5V operating threshold. This doesn't mean that your 33 psi (~47.7 psia or 4.8V) isn't accurate, but going much beyond that might be questionable. I'm glad you brought that up, made me look into it a little deeper. 
Who replaced the MAP and O2 sensors for you? Dealership? Harvey? Do you still have the *old* sensors? If they were replaced based solely on P1235/P1238 codes then you may just replaced perfectly good sensors.
Get in touch with DG Motors/GST Motorsports/HBSpeed..., they spend a lot of time on here helping people with tuning issues and should be able to help you out as well.
Here's a thread that will be of some use: https://www.evolutionm.net/forums/ev...p1238-etc.html
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