The shop that has been keeping my Discovery 1 on the road for several years temporarily fixed an engine problem with a used OEM MAF sensor. This fix worked fine for a couple hundred miles-- then, on the next trip, the Rover barely was able to limp to the shop. Another (used Lucas) sensor was installed at the shop and got the truck home before failure again. Since we are now a (very) long distance from the nearest LR shop, I guess I am now my LR mechanic. When the shop installed the MAF sensor, the mechanic was concerned that it might not last too long and should be replaced. He recommended that I buy OEM, but aftermarket might work. Since OEM price is not much less than I could get for the vehicle, I bought and installed an aftermarket sensor. This did not fix the problem. If anything, the engine ran rougher with the new sensor. Since we have owned the Disco for 18 years, it is part of the family and I am not ready to give up. I "bit the bullet" and spent the $1400 for the OEM sensor. Now, since I am ready to install this pricey hardware, I want to be sure I prep everything appropriately, don't mess up and damage it. The combined knowledge of the forum could help to keep me out of trouble! Some questions would be: Should I clear existing codes? How about the method of booting the ECU by disconnecting the battery and grounding the pos. lead? Should I do anything about existing codes (like cylinder misfire and O2 ) before installation, or wait and see if the new MAF fixes everything? Suggestions will be appreciated

 

what year is your truck ?
yes ...clear the codes, check the air filter condition ( i would replace it if it's not already new), clean the throttle body , new spark plugs and wires would be good....which may help the misfire and o2 codes, i wouldnt attempt to disconnect and ground the battery pos lead.......clear the codes with a code reader.....see how it goes

if you have a vehicle older than 1996....there,s a different method to clear the codes

 

The truck is a 1997, which I understand is the second year of the OBD2 standard. Thanks for the sound advice! Even though the shop did a complete service in November, the engine has been running badly for long enough to (at least) dirty the plugs. I should have results of the new MAF sensor in a couple days.