so im getting these codes after my headgasket swap. After several google searches im getting mixed answers on what they actually indicate. But generally im seeing vacuum leaks and maf sensor being the usual culprits.

My maf sensor is only about 4 months old but is a cheap autozone part. does parts store sensor reputation warrant ordering a new bosche unit or should i do some more investigating first?

i havnt completely ruled out vacuum leaks but ive narrowed it down to either the upper or lower intake gaskets if it is in fact leaking air. all other vacuum hoses/ports are nice and tight.

 

Too rich would usually rule out a vacuum leak.
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Well that's what I don't understand. Given those definitions, doesn't it mean the computer has added as much fuel as it could with no luck? Or the opposite?

 

When my D2 popped 1171/1174 too lean I found a couple of small vacuum leaks and issue resolved. Your experience may vary and will be interested in others' suggestions.
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Does it say anything that my long term fuel trim on both banks is fine? They both stay positive but never exceed 10%.

I looked at the freeze frame from the 1172 code and there wasn't anything odd that I could see. The short term trims are wonky but those are are supposed to be constantly bouncing around right? Here's a pic of it.

 

Before you put in new headgaskets, antifreeze can go out the exhaust valves
and run the O2 sensors.

i have a write up about this
http://jeffreyfall.com/landrover

 

I could see that being a possibility, but it was a very small leak. I almost wasn't even sure at first if the gasket was compromised as it wasn't actually broken and the offending cylinder was only very slightly cleaner than the others. Plus it's throwing codes for both banks, does that normally happen with only one sensor is failing?

 

Getting a little concerned about this guy's. My coolant Temps are never getting above 198 and even then it's usually
​​just momentary at idle but I'm worried that my coolant temp sensor might not be riding correctly. This would explain the codes as the computer can't tune correctly.

Coolant isn't boiling over and I can find any leaks but just got out of the truck to see a movie and got a heavy coolant smell. Ambient Temps are low 40's here but lower rad hose is never getting hot, stays like 30-40 degress cooler than upper radiator hose

 

The old-timers on this forum (one in particular) were adamant that if the MAF needed to be replaced that only the Bosch unit should be installed. They described what you're seeing, that he aftermarket units all too often failed quickly.

There is a lot on info online about how to test a MAF with a multimeter (not Rover-specific). Just Google "test MAF." I have never done it but it looks pretty straightforward. If you test it and find it's defective return it and buy the Bosch.

The old timers were also adamant that if you decided to clean the MAF do so only with the truck an sensor fully cooled down to ambient the ambient temp.

 

Just read this. Can anyone confirm? Would be nice to save 100 bucks.