Keith Browning Posted September 25, 2007 Share Posted September 25, 2007 We have touched upon this topic in one way or another before. This time its a P006A - MAP - Mass or Volume Air Flow Correlation with a P0401 - EGR low flow detected. Oh fun! This truck has some miles on it but it runs well, has the latest calibration in it, a new EGR valve and a new air filter... Since this truck has the inferred EBP calibration in it, the MAF code becomes very important since according to engineering it is vital in determining EGR operation. I dismissed the P0401 for now but not after hitting it with the IDS EGR tests which passed. This brings us to pinpoint tests J13 - J14 and TSB 06-24-6. No leaks, sensors correlate but I noticed in my travels through the streaming data that the MAF signal looked too fuzzy and I could not get a good read on it in performing the TSB but it all checked out! /forums/images/%%GRAEMLIN_URL%%/popcorn.gif The filter! Its an aftermarket paper cone inside of the filter cartridge. Ah ha! I sold the customer an new Donaldson filter and performed the Turbo Learn procedure. This cut the fuzzy signal by 2/3rds. Hotline reports that the new calibration on these early build trucks is REALLY sensitive when it comes to MAF signals. REALLY sensitive. Apparently this filter was causing some disturbance in the airflow through the sensor? Makes sense but this being my first run-in with a cheap filter and the inferred EP calibration the proof for me will be no MIL for a 100 miles or so. We are putting miles on the truck before returning it. I wanna be sure! /forums/images/%%GRAEMLIN_URL%%/wink.gif Quote Link to comment Share on other sites More sharing options...
DwayneGorniak Posted September 25, 2007 Share Posted September 25, 2007 I have seen this with cartridge inserts made by "Green" filters and the AFE Itself. Also with aftermarket exhaust systems because they draw more air through the engine. And yes these early birds are quite sensitive. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted September 25, 2007 Share Posted September 25, 2007 Hotline reports that the new calibration on these early build trucks is REALLY sensitive when it comes to MAF signals. REALLY sensitive. Apparently this filter was causing some disturbance in the airflow through the sensor? Ditto with Dwayne. It's not just the 06E17 calibration, it's all of them. I've seen several times where an aftermarket air filter caused EGR codes. It's important to clean both the MAF and the IAT2, also. I can tell you a horror story about a Taurus with a twisted OE air filter that caused fuel trims to whack out and P0171 codes. The cause was turbulence in the MAF housing from air flow around the air filter. Good Luck! Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted September 25, 2007 Author Share Posted September 25, 2007 In the past I have had a couple of P0402's due to exhaust mods. This truck was in my shop a few weeks ago with the MIL on. It received a new EGR valve and I did clean the MAF and IAT2 sensors which has been my regular routine for some time now. The MIL came on two days later. The interesting part is, the customer came down to see the truck because he had just spent a lot of $$$ having the truck "fixed" by his mechanic. We won him back! (maybe it was my charm) Managed to up sell some service just by pointing things out under the hood while he was there... including that new paper filter. /forums/images/%%GRAEMLIN_URL%%/shocked.gif If I realized then this was going to happen... Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted September 27, 2007 Share Posted September 27, 2007 Quote: We are putting miles on the truck before returning it. I wanna be sure! Had the same situation, didn't want to believe it could happen. Customer was in shop every week with mil on. Finally put air filter back to stock and he's been on the road for over a month with no problems. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted September 27, 2007 Author Share Posted September 27, 2007 Oh shit! I forgot to drive the truck today!!! /forums/images/%%GRAEMLIN_URL%%/rotz.gif I AM losing my mind! Quote Link to comment Share on other sites More sharing options...
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