I have a 2000 disco,and the check engine lights keeps coming on. i replaced the engine head brand new, new air filters, 4 o2 sensors, oil change, new plugs, what else....... my mechanic says he doesn't see any thing major needed but mind you i need to get my vehicle inspected already tried and it failed because the light came off just my luck it came on when time to inspect... i got the codes read, po141, po160,po161, po171, po174, po734,p1172, and po1175. The disco is in excellent shape and runs smooth since i replaced the engine head, but the light is the problem... after reading some post, i was thinking i have to change the tranny fluid but i know for a fact thats not the problem.......Please help i will gladly appreciate it.

 

You need new rear O2 sensors. Replace all 4 though. The P0734 may be your MAF but do the O2 sensors first.

P0141 O2 sensor heater circuit malfunction (bank 1, sensor 2) Rear sensor heater LH bank - short/open circuit (NAS and EU-3 only)

P0160 O2 sensor circuit no activity detected (bank 2, sensor 2) Rear sensor RH bank open circuit (NAS only)

P0161 O2 sensor heater circuit malfunction (bank 2, sensor 2) Rear sensor heater RH bank - short/open circuit (NAS and EU-3 only)

P0171 System too lean (bank 1) Multiplication injector adaptive fuelling - lean limit
exceeded LH bank

P0174 System too lean (bank 2) Multiplication injector adaptive fuelling - lean limit
exceeded RH bank

P1172 System too rich (bank1) Additive injector adaptive fuelling - rich limit exceeded
LH bank

P1175 System too rich (bank 2) Additive injector adaptive fuelling - rich limit exceeded
RH bank

 

Thanks for the response. i had the O2 sensors all 4 replaced already.

 

"i had the O2 sensors all 4 replaced already." Did the shop who did the work use OEM sensors, or universals?

 

Have them put new rear ones in as they are dead, the computer is not getting a signal from them. It happens. Keep your fingers crossed it is not a computer issue.

 

Most 02's have a 1 year warranty so have them deal with that. Once that is done, if you still have the lean codes and the 734 tranny, then you will also need a new MAF which you can buy and install for less then what the shop will charge.

 

agreed. go back to the shop and make them replace the rears again. should warranty their work and parts.

 

i'll get that done today, keeping my fingers crossed. thanks alot for the ideas, ill let you guys know once i get the problem fixed. ok i have to take my baby to the shop (hospital)..... feels like it...

 

also the mileage number is blinking can anyone tell me whats causing it to blink?

 

its not synced with the ECU. in my case mine blinks because i put in somebody elses cluster to replace mine because a few of my LED bulbs were out. When your mileage on your odometer differs from the ECU it gets upset and blinks till its fixed. I brought mine to the dealer and they said they don't know how to sync a used cluster although people on here said it is possible. good luck.