hey everyone had the rover for a few months now and she is still all i could ever ask for but the obd system has got me, i have a scaner that gives live data and there is no reading from the MAF, the fuel system does go into closed loop but she still pees fuel like a big dog, idle is fine at 750 rpm and timing adv on cyl 1 is 30%, O2's S1B1 0.96v +24.2% fuel trim S1B2 0.915v +24.2 s.t. fuel trim S2B1 0.01v S2B2 .005v, air intake temp 123 deg f, cool temp 152 deg f, short term fuel trem +24.2%, long term fuel trim -21.1%, the two 02s that are down stream look shiney new the up streams look like hell, can i swap them to get it to run better it is pre ael all 4 are the same, will the other two still read if the cats are working or do i need to spend the big money, also i know the maf needs to read but when they go do they just quit, is the iat sensor reading 123 from under the hood bad when it's 6 deg f out side right now, any help would be great until then i'll be a jeep'n thanks agian

 

That's a lot of data from your scanner. What are you using?
Clean O2's and Dirty O2's: that's normal. Do an Intake Manifold cleaning, then "SeaFoam" treatment the engine. last, run one can of SeaFoam through the fuel tank. When you look at the O2's before the cats, you'll see them cleaner.
When the O2's before the cats are dirty, the CEL comes on: lots of $$ to replace. The alternative is to clean them with SeaFoam in the fuel.
The O2's after the cats are the same but their only function is to tell the ECU that the cats are gone bad.
The IAT reads higher on mine too. Right at start-up the reading is about 5f higher than the ECT. After the engine is warm, the IAT reads 40 Celsius more than the outside temp (I've removed the air horn to make room for the second battery so the intake pick up takes air from the engine bay i.e.: hotter)
We need to know more about the engine: how does it run, what codes you get, what fuel you use, last time plugs and wires were changed and with what.

I use OT-2 for live data, what do you use?
SD

 

You can swap the pre and post cats O2's.
If your intake air temp is reading to high of a air temp when you just start it or while going down the road then it is bad.
But while idling it will read the underhood temp as it sucks in the warm air from the engine.

 

i use an elm 327 obd usb scanner, there is no cel or mil what ever your choice is there, i have changed the spark plugs with bosch single platinum ones, have had bad experiences with the +4 junk in my pathfinder and wrangler, the air intake temp sensor just kind hangs there because there is a cold air setup on it and i have got to putting in a new hole yet but yeah i was at a stop with it idleing in my drive way, how much incorrect fuel dumpage will go on with a bad MAF, and is there anyway to test it with my multimeter, check resistance or measure current or voltage, i'm not to sure my jeeps use a map sensor, so my oxygen sensors should get that reading when the maf is dead and just pisses fuel through the exhaust, so who has a good maf to sell or where can i get one cheap i think mine is the 5595a type. thanks again for the help insight to fixing the brit beast

 

changed the maf and nothing on the reader still max neg value for the air flow meter, got a chance to test the wires the red and black was ground and the orange and brown is power when ign is on, didn't get to test the other wire with it running i was soaked its pouring here, but what should i get from the third wire the ecu feed some where between 5 and 0? and if i get a good reading at the sensor then i must test the loom or harness i know what pin it is i looked it up in rave, but if my harness is good then the ecu is junk??? any help would be great i would love to drive this beast agian. thanks agian