I'm away from my references but this doesn't appear to be MAF related...

This is my old Boxster, now owned by a friend. The CE went off after the swap, now with subsequent driving it has come on again, apparently with the same P1126. I'm not sure if he cleared the code along with the swap. Does this code indicate for a rear sensor, too? (Thought it was for one particular side at the front.)

Minus 40 degrees... Is that Fahrenheit or Celsius?

Bank 1
– Incorrect signal from MAF sensor
– Intake air system leaking
– Fuel pressure too low
– Volume supply of fuel pump too low
– Fuel injectors fouled

From reading this I get the sense there is too much air and not enough gas. There is also mention of an exhaust leak as a cause.

The flow chart says test the MAF, then exhaust, then air intake, then fuel, then injectors.

Minus 40 degrees... Is that Fahrenheit or Celsius?

but one bank may be more sensitive and the DME reaches its error code setting threshold first. Because the CEL is now on the driver drives the car differently,much less, and the other bank never gets a chance to trigger its related error code.

Sincerely,

MarcW.

Minus 40 degrees... Is that Fahrenheit or Celsius?

by looking at the fuel trims (which are bank-specific) with a standard OBD-2 reader.

Now I have to hose down my interior and see if I get tatooed.

Minus 40 degrees... Is that Fahrenheit or Celsius?

What was the nature of the code before the swap? Did it come on soon after every time you cleared it?

The easiest thing to try is run a bottle of Techron through the fuel system.

I'll suggest we get some Techron into it, as it's my ride to the dealer, about 40 miles away.

Minus 40 degrees... Is that Fahrenheit or Celsius?



Edited 1 time(s). Last edit at 06/28/2012 11:54AM by Laz. (view changes)

But just in case you are awae of the 'trick' disconnecting the MAF at teh harness, clearing the error codes (to reset things) and driving the car to see if the error codes come back?

Let us assume that the other bank didn't trgger its error code because the failure more is not a common one, but limited to one bank.

Since I see a mention of an air leak that suggests the problem is related to not enough fuel or too much air.

That's an intake air leak and this can arise from a failing AOS, cracked oil filler tube, a leaking oil filler tube cap, and of course intake air leaks anywhere in the intake system. However, these are common failures unless the air leak in the intake system is limited to one bank and its intake runners, etc, none of the above seem like top suspects.

On the not enough fuel side this can arise from a blocked injector. The DME will add more fuel to all injectors until it gets the results it wants or until it runs out of adjustment, or until the healthy cylinders start misfiring due to too much fuel.

A blocked, bad or an injector that is otherwise not delivering the correct amount of fuel given circumstances or a pinched fuel line then becomes a possible cause.

I kind of like one of the above based on the info I have at hand.

Anything done to the engine recently?

A blocked fuel filter, or low fuel pressure are common failures. However, I think they belong below other possible causes.

Sincerely,

MarcW.