I Searched the forum, but no luck. I have a complex issue.

P0101 is back after my 147000 spark plug change that I posted that I thought cured from getting rid of P0301 and P0101 - 7 months ago.

NOW 165000 MILES-ISH

I am lacking some schematics or pictures / on where the ground points are on the chassis for checking MAF /ECU grounds???.

7 Months ago:

- Replaced the MAF with a Hitachi
- Replaced the plugs
- Pulled the 4 year old battery out of the tray that was nasty green and cleaned / burnished everything
- Both codes went away

Last Month to Present
- P0101 is back.
- Took to dealer $350 to reprogram the ECU and they advised it probably needed a stock MAF
(Sub note: also took in for CVT going into failsafe they advised me I needed a new trannie, two 4 qt oil changes (Amazon $62.00 and the right fluid level cured that one)
- P0101 light back on the next day.
- I put the stock cleaned MAF back in that I had kept that I thought was probably not bad anyway.
- P0101 came on that week.
- Cleared again took a very long 1000 mile road trip for work Never came on
- Drove in town in the city for a couple days P0101
- 2 cans of brake cleaner – Really never found a vacuum leak.
- Pulled of top cleaned throttle body butterfly (yes I used the brick trick to open the thing up with the gas pedal and did not force it open)
- Erratic idle subsided a little seemed to be running good 2 days later P0101
- Checked all of the intake piping downstream from MAF to throttle body everything looked good from my spark plug change and everything was where it needed to be (NO CRACKS EITHER)
- Replaced battery that was crusting up (cracked post seal) and replaced the connector part because they were trashed thinking it was getting voltage spicks in tow nwhen the alternator could not keep up.
- P0101 Next day
- I did all of the learning resets per the book yesterday, and Poof P0101 within 12 city miles.
- Last night I reset it again and then decided to pull the middle section of the snorkel out to see if it was related (Like the K&N issues everyone has had)
- No light thus far today two trips work and back…………..AND FUEL MILAGE UP 3-5 mpg


• I saw the procedure for checking voltage etc. and the ground however cannot find a picture of print on where the main ground is for the ECU and the MAF?
o If someone has this schematic or can take a picture where they are in the engine compartment that would be great.
• I found a crusty connection (ground) under the middle section of the snorkel next to the battery tray…………IS THAT BOX THERE THE ECU or the engine fuse box?
• I am also wondering about the bottom section of the snorkel, it is able to rotate about 15 degrees in both directions
o This caused me to think maybe I hit road debris and broke it loose from the grill which would rob the air cleaner of force fed air??????
o Does anyone know if this piece should be rigid mounted?

******I NEED TO MENTION THAT BEFORE CLEARING THE CODE THE CAR SMELLS REALLY BAD AT STOPLIGHTS AND IN THE GARAGE ITS RUNNING VERY VERY VERY RICH when the SES light is on.

After I clear the light the rich smell goes away.

Any help on any of this is greatly appreciated.

1. Bad ECU?
2. Walmart Fram El Cheapo air filter not letting air through (been running this filter since 2011)?
3. Snorkel busted?
4. Bad ground?
5. Bigfoot?
6. Lock Ness ?

This morning to work, still no light with snorkel off middle .......30 MPG vs 22 MPG WTH?

- Well last night on the way home popped a SES code have not read it yet.
- Put connecting pipe back in fresh air snorkel.
- left code in it and did not clear it
- Today, no heavy rich smell like normal when light lit and gas mileage still up about 4-5 mpg?
- Does anyone have the ECU or MAP grounding diagrams please......or maybe my ECU is just retarded they supposedly reprogrammed it the other day?

Update: Stopped by THE Zone read the code shocking but P0101. Gas mileage has gone through the floor again and rich smell is back after letting run for a few days. I did a 30 min neg term disconnect at lunch code cleared and rich smell gone. Disconnected cold air snorkel intake again gas mileage back up +4-6mpg. I have a theory......

I believe it may be the Ambient Air Temp Sensor there appears to be a TSB out on the sucker breaking loose or something. The printout I got from AZone states it that "When not replaced, vehicle may experience failed emissions test, RICH or LEAN running condition, EXCESSIVE FUEL consumption, and CEL illumination.

I also read somewhere where it can throw off the ECU enough to screw up the voltage being sent to the film of the MAF.

Anybody have any input?

OK dug around at lunch and it all makes sense now why this problem has been off and on for a year and 1/2 now.
I took my MAF connector off and Had 12.4VDC and 4.8VDC Turned off car and rang ground out only to find it not ringing but 59.7 Ohms on both the grounds
I pulled the air cleaner to try and trace the wire and found a big old harness underneath. It has a big old honkin split in it (plastic shied and a bunch of water and juice down in it )
The leaking battery post let acid get back behind and run down the air filter housing and that's where a big harness sits that the air cleaner basically rest on.
So when i pulled the fresh air middle section and the filter housing out the other day I must have manipulated the wires enough to get ground back.
I went ahead and stuck my finger in the gash and moved all of the wires around in the harness, then re-read the grounding on the MAF and low and behold it rang out.
Put everything including the air piping back together drove to work with 27-30 MPG and spirited driving of course even mixed in.

So it appears that it is possible this harness needs to be repaired or replaced however looks intimidating.

Anyone ever replaced this thing????? it goes to the engine and splits etc, I will look through the forum later. Maybe should just suck it up and have the dealer do it?