So my son just inherited a beautiful 1997 money pit...errrr...I mean Land Rover Discovery 1. All jokes a side we are super exited and it was an extremely nice gesture. He is 17 and we really needed an extra ride for him to get to work and school and thought this would be cool car cause...well...free and all. I have to preface this with the fact that it has been impeccably maintained and I have every single work order for every job written up on the car. Because this car was purchased and owned out of state, I went through the out of state to California registration and title transfer process which, of course, included a request for a smog check. In order to ease his way into the world of car ownership, I told him "hey, I did all the difficult paperwork (put it in my name), you find time to get the smog done"....which he did before I had a chance to go really go over it with him. Turns out he already misplaced the gas cap. In his defense, he was use to driving my wife's escape prior to the Disco, which does not have a gas cap so he wasn't use to replacing it after filling up.
So at the smog check, automatic fail for no gas cap. I also wasn't aware of a check engine light which was throwing the P0300 and P1316 errors on connection to the OBD. I wanted to try and help him do some work on it (per his request) to get to know the car (and cars in general). So...to my question:

• The plugs and wires were replaced, from what I can tell, in 2009 at 90k miles (Duralast). The car is now sitting at 145k miles here in 2022. Is this a good place to start? I don't mind forking out the money to just replace them as opposed to trouble shooting each plug as they are probably due to be replaces
• The smog tech informed him that he would need to drive the car approx 150 miles to clear the codes? is that really necessary? I did read somewhere in my research that it could be accomplished at 50 miles.. Also, cant I just clear the codes try for the smog again?
• Im not sure what to expect from the perspective of fixing an issue, driving it 50 miles till the check engine light goes out. If thats not the fix will it go out and come back on if the plugs weren't the issue? Hows the process work

Any thoughts or advice is appreciated.

 

Welcome to the forum!

Didn't see the check engine light on? Tsk tsk tsk.

I'd do the plugs and wires first, and re-set the CEL, then do some driving and see if it returns. And yes, of course you can and should clear the codes and re-set the light after the work. Oh and put the gas cap back.

No, the smog tech was wrong and it doesn't need to be 150 miles. But it's not 50 miles either. It's when the computer determines it's ready for the check. It's the "smog readiness" flag, or something to that effect and it's re-set once certain parameters are met. You MAY be ale to find them for a '97 D1 somewhere, but generally driving around city AND highway will do it. It's things like >10 minutes at more than 50MPH, x number of heat cycles, etc. I believe the Torque app has the ability to detect it and so should other decent OBD tools. You can't tell if/when it's ready for testing without a tool to read it, so techs over-estimate the time it may take.

You're running premium, right? Drive it until the smog readiness flags are re-set, or until the CEL comes back on and post back. Good luck!

 

Thanks Bud. Ill get right on the plugs and wires....any brand recommendations?
As for the premium gas, I would say no and I would also say my sons head might explode when he hears that. Hes 17 and already complaining about gas prices. Was the a manf. rec for this car? or something that all you old disco drivers recommend.

 

Yes, it's required per the manual. 90 or 92 AKI, 95 or 96 RON. Here in the bay area, it's the premium 91 octane. The computer is programmed to expect that fuel and it can and will "knock" with lower octane. Think of a knock as a type of misfire. You know, like the ones you're getting codes about....

If you're low now, I'd fill it up with 91 (prepare to hit the max allowed purchase at the pump!), drive it long enough to ensure you're drinking primarily the good stuff, and drive it some more. If the light goes out, stop by the smog shop, you're g2g. You may get lucky and not need to get the plugs and wires. With 50k on the current ones, it certainly wouldn't hurt though. And it's something a 17 year old can do. Search the forum for recs.

 

Just wanted to update ya. We put the plugs and wires in this weekend. My neighbor happened to have an OBDII reader he got for christmas. I plugged that in and ended up with a 3rd code P1179. After the spark plug replacement, we reset the codes and went for a drive. within 5 mins, the CEL came back on, but after and OBD scan it ended up just being P1179 so it looks like the misfire was gone. We filled it up with premium and within 10 mins, the CEL went off and we have no more codes. Im gonna give it a week of driving and, fingers crossed, if the CEL stays off we will run it back to the smog shop.
Thanks a ton for the help and for saving me, im sure, a ton of dough