Hi guys,

I have a 1998 Range Rover, with 108k. I have just recently changed the plugs, wires. I took off the other day about 2 minutes into the drive it started stumbling and losing power. The check engine light came on. I keep driving until the engine temperature got to the normal range and the engine smoothed out. It's fine once the engine gets to normal operating temp. I changed the fuel filter and that did not help. I read it another post saying it could be the o2 sensor. Which one should I change first? The codes I got was P0303 and P0300. So I figure I need to change one of the drivers side O2 sensors? The Rover idles fine. Any help would be greatly appreciated.

Thanks,
Jason

 

303 is a #3 misfire which carries the 300 code also.
I see nothing indicating an 02 sensor, that being said at your mileage, I would change out all 4 02's to get some long lost performance back with a better air to fuel ratio.

 

Thanks Disco Mike. Do you know what would cause the stumbling and loss of power before the engine warms up?

 

What octane gas are you using, when did you last run a good additive, BG 44K, thru your tank and who's plugs and wires are you running?

 

It's been about 3 months since I put a bottle of Lucas injector cleaner. I run 89 and 93 octane gas. My plugs and wires are both NGK. Both plugs and wires are about 2 months old.

 

I'm now having a problem starting it when its cold. It will start and then cut off (runs terrible at this point). It will do this a few times and then it starts and idles fine. If I drive off without letting it warm up it will stumble and seems not to take the gas. But once it warms up it runs great. Any ideas of what this could be? Thanks.

I just checked the codes again. There are some new ones.
P0300
P0303
P1177
P1316