A the title says.. Can I safely run my Fiesta with the Mass Air Flow Sensor disconnected?

Car runs fine with it disconnected, however, once i connect it - it runs like a ... 3 legged dog pulling an anvil.

It controls the air/fuel mixture so without it the ecu will run on default mapping and it can cause poor mpg and emissions issues. You would be better of cleaning the MAF with some isopropyl (carefully) or buying a new one.

As yours is 11 years old it has probably burned out now (it runs at extreme temperatures and the metal wires break down) so get a new one.

in short - yes, you can run the car, but you can expect more smoke and poor emissions / possible poor running as Rick suggested, and you will likely see the EML come on to say hello.

Otherwise as Rick says, best bet is to clean it (you can also use electrical contact cleaner) or replace as necessary.

You'd kill the piston rings due to over fuelling but it'll work for a while, just get a 2nd hand one from the breaker or eBay.

Edited July 29, 201411 yr by Stoney871
Removed Ap Tag

I've learnt this lesson the hard way, so I say avoid the cheap copy alternatives on Ebay etc and buy one from a good quality manufacturer at the best price you can find. Lots of excellent parts suppliers on Ebay,Amazonetc ( like Victoria auto parts) that offer quality parts at the right prices.

I was going to clean it - but looking inside, there was only 1 of the 2 wires needed, so needing a new unit.

However as the car was sold as having had a service, this should have been picked up (that and the missing engine mount - no idea how it passed its MOT), anyway, it's getting the service it needs on Friday - woot.

good result, as long as these are replaced you should be fine!

I suspect much like a car I bought from a backstreet garage, they just printed a certificate without looking at the car. Anything just to get it out the door, and they can blame the driver for anything that goes wrong inbetween!