Yesterday while driving my 1999 Disco II the check engine light came on. The car appears to be running normally. It may have a little loss of power or I may be just imagining that. I have a OBDII code reader and I checked the codes. To my surprise I had 10 stored codes. I reset the PCM and the check engine light went out. I drove the car about 5 minutes and once again the check engine light came on. I once again looked at the codes and the same 10 were displayed. I took a ride in the Disco and used the live data feed to look through all of the screens. There is data present in for all of the values with the exception of the MAF sensor. The reading for the MAF stays at 0.0 not matter what I do. When the PCM is reset, the codes come back as soon as I start the engine, even though the check engine light may not come on for a few minutes. For those who are familiar with these machines, do you think I need to replaced the MAF? Are there any other checks I can make to help eliminate my trouble? The codes that come up are P1884, P0102, P0445, P0448, P0340, P0134, P0154, P0135, P0155 and P0147. Everyone here helped me complete my head gasket replacement several months ago and I feel confident help awaits me for this problem also. Thanks to all.

 

I see some O2 sensor codes looks like at least your front 2 are bad (134, 135, 154, 155). I would replace all 4 as they need to replaced in pairs (front and rear). That may clear up all your codes so I would do that first. AB has them on sale for $60.

 

Thanks lipadj46 for the input. I would find it difficult to believe more than one O2 sensor to fail at once, thus I was thinking it was something upstream from the 02 sensors.

An added note to the my original post. I drove the Disco to church this evening. It definitely has some power and/or torque issues. I had the car on cruise control and I noticed it was downshifting on small inclines that it usually does not downshift on. Any other ideas would greatly be appreciated.

 

Well they do go bad and maybe something upstream caused them to fail.

 

Start with a new Rover MAF, not an after market one like NAPA sells.
How many miles on your engine, if over 100,000 replace all the 02 next.
I am not worried about the 1884, it will go away with the replacement of the MAF.
The evap codes won't effect how the engine runs but the 340 can be a real kicker in your case. You don't see a cam sensor fail often on a Rover. Look at this as you last item to replace, they are expensive and I would want to make sure the the MAF is not driving this code.

 

Mike,

I ordered a new MAF today and will update this post once I get it installed. My Disco has 88,000 miles on it and I replaced one of the 02 sensors last year. Thanks for the input.

 

I have the same issues including random shutdown. I have also ordered OEM Mass Airflow. Will tell how it goes after install. I have already replaced crank case sensor thinking that may be the cause of the random shutdowns.

 

I replaced the MAF with high expectations. Sadly, I still have the same issues as described in my initial post, including the same codes stored. The new MAF is a Bosch unit, as was the one I removed. As soon as the Disco is started the "check engine" light comes on. I can reset the light and it goes out. I rev the engine and have drove the Rover about 15 miles without the light coming back on. As soon as I turned the car off and restarted it, the lamp returns. I have taken electronic contact cleaner and cleaned the MAF electrical connector. The car definitely has a sluggishness that is not good. Any other inputs would be greatly appreciated.

 

Did you MAF come in a Rover box? If not you don't have the correct one. Bosch makes many generic MAF, look the same fit the same but won't work.
Look at the part number on your original MAF and compare it to the new one.

 

Thanks for the input Mike. Your wisdom is appreciated.

The new MAF came in a Bosch box and has the identical part number stamped on the MAF as the original MAF. I looked at both prior to installation and once again now to be sure I did not over look something. I ordered it from autopartswarehouse. What would you suggest as my next move in this game of LR chess?