# 95maxima - codes MAF, EGR and knock

**URL:** <https://community.cartalk.com/t/95maxima-codes-maf-egr-and-knock/36865>\
**Category:** Maintenance/Repairs\
**Tags:** nissan, maxima\
**Created:** [September 20, 2009, 12:17am UTC](https://community.cartalk.com/t/95maxima-codes-maf-egr-and-knock/36865 "2009-09-20T00:17:18Z")\
**Posts on this page:** 2\
**Page:** 2

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**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\
**Post date:** [September 22, 2009, 1:11pm UTC](https://community.cartalk.com/t/95maxima-codes-maf-egr-and-knock/36865/21 "2009-09-22T13:11:09Z")

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If the engine runs a little rich, for whatever reason, at first you’ll get an increase in power. MPG will drop sharply before it’s rich enough to reduce performance.

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**Author:** ![brokemaxownr](https://avatars.discourse-cdn.com/v4/letter/b/bb73d2/32.png) [@brokemaxownr](https://community.cartalk.com/u/brokemaxownr)\
**Post date:** [September 22, 2009, 1:24pm UTC](https://community.cartalk.com/t/95maxima-codes-maf-egr-and-knock/36865/22 "2009-09-22T13:24:30Z")

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I agree it would probably have better cold start idle/drivability bc of the fuel enrichment. But would someone (especially your average cellphone talking/lunch eating driver) really notice a power increase at very light throttle openings?

If the AFR went from say 14.7 to 12.5 (which anything below 12.5 would just load the plugs) at idle, I would imagine the only thing they might notice would be the mpg dropoff.

Rarely is there much of a power reduction (even at full throttle) from say leaning AFR from 12.5 to about 13.5. Usually its only about 2 percent on a dyno.

I bet the only way they would catch it would be walking behind it and tearing up the mucous membranes.

Kind of hard to test this much. While I can adjust AFR of my carb in my camaro to just about anything I want, I can’t control it at all rpms. And most EFI motors you can’t get that adjustment period. Certainly not closed loop.

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