Hello, I own a 2000 Discovery II with 105,000 miles. This is a two part question I guess, but I figured I would put them both on one thread incase they are related. Although, I don't think they are. My first questionis, is it normal for the secondary air injection pump to run at a higher rpm for the first minute after startup? Secondly,I am getting codes P0174, P0150 and P1174. The engine runs fine until it warms up, then it idles roughly. The only problem I've had up until now is a bad crank position sensor. I replaced plug wires and plugs 25K miles ago. Other than that, just oil changes and air filter changes every 5K miles. Any insight or advice would be greatly appreciated. Thanks

 

What have you been using for an air filter, paper or oil covered like a K&N? The reason I ask is you have 2 lean codes ythat are usually found when the MAF has died. The 3rd. code is an 02 circuit failure code and by mileage, you are ready for 02's.
So 4 new 02's and a MAF and you will be set.
The 02 are best bought at Atlantic British, the MAF from Tony at Cerrones, 650-365-4145.

 

check your engine for vacuum leaks, look at the air intake tube, and all connections going to the plenum

 

I checked for leaks today. Couldn't find anything. I figured it was time for oxygen sensors. I had only cleaned my MAF, not replaced it. I guess I'll put that on the list of things I will replace. I currently have a plain paper air filter, but I plan on getting a K&N. I looked at the local auto store and their applications guide didn't list my vehicle.I found the part number for the K&N for the Disco. II online and just need to pick one up.

I'm going away for the holiday and won't get right on this, butI'll keep you posted on what happens.

Thanks.

 

Cleaning a d2's Bosch MAF will kill it just as using the K&N filter again.
When you get ready, call Tony at 650-365-4145, he has about the cheapest price on line for a new MAF.
Also, throw that K&N away.

 

Changed all four oxygen sensors, the air filter, and the MAF sensor today. Rough idle has gone away and hasn't kicked out any codes yet. I've only driven it thirty miles though. I'll keep everyone posted. I'm going to change the coil packs, plug wires and plugs later this week. Looks like no easy task. Mounting the coil packs behind the intake manifold was ingenious engineering.