My "newtome" DII is serving up codes buffet style, advice please.
 

Just ran the codes and it appears all 13 (YES 13!) are dealing with the O2 sensors and cylinder misfires (except for unknown P1300). This is my first LR and I could use any and all advice/knowledge/experience shared!

P0134 - o2 sensor
P0154 - o2 sensor
P0161 - o2 sensor heater circuit
P0135 - same as above
P0155 - same as above
P0141 - same as above
P0160 - o2 sensor no activity
P1300 - definition not found
P0306 - cylinder 6 misfire
P0305 - cyl 5 misfire
P0300 - multiple cylinder misfire
P0303 - cyl 3 misfire
P0308 - cyl 8 misfire

I've got a large gasket job I'm pricing out right now while the entire gasket set is on its way from AB...so questions I'd love to get answered!

1. What all needs to be done?
2. What should be my priority?
3. What to get done while doing gaskets job?
4. Should I be locating a good machine shop right now?
5. Are the rear o2 sensors least important right now?

I just cleaned the throttle body tonight right after the diff fluids change, but as you can see with the cylinder misfires...it isn't running real strong!
Thanks in advance!!!!!!!

did you order new head bolts with your HG set? you should also put a new thermostat in at that time. do you plan on doing the HG yourself? if so then find a machine shop to inspect and possiblyt resurface the heads. You should also fit some 8mm magnecor wires and some bosch plat +4 plugs. Put it all back together, clear the codes, then read the codes again. Half of those codes should be gone. Than you can be positive you need all 4 o2 sensors replaced.

also do the rest of the 60k maitenance, swapping all the fluids.

Just checked the codes again after only driving about 2-3 miles since clearing them and got 8 repeat codes, and i'm pretty sure it's only a matter of time before the missing 5 from previous run show up.
Also of note, each time i've started it up after clearing the codes the 3 amigos have shown up, but once I start it up again they are gone.

Here are the 8 codes:
o2 sensors - P0134, P0154, P0135, P0155, P0161
cylinder misfires - P0308 (cy8), P0306 (cy6), P1300 (mult)

So...should I go ahead and order new plugs & wires? The wires don't seem to be too old and I don't want to start a debate between 7mm & 8mm, but I do like to hear what others use, have liked, and why. AND I wouldn't mind getting newer better ones for my piece of mind anyways. My rig currently has Belden Premium 7mm class F wires on it...they can't be very old, but I'm up for replacing them anyways.

Any other knowledge, wisdom, or experience that can help lead me in the right direction?

Thanks in advance!

I haven't actually placed the order yet...was looking for the advice on priority and what else to check/replace first. I have been made aware to order the head bolt kit and thermostat with the gasket set, so thank you there.

I won't be doing the gasket job myself, until I purchased this LR I hadn't done much beyond checking/filling fluids and putting gas in a car! But I'm very motivated and really enjoy learning everything I can do myself. My helpful bro-in-law has been holding my hand through the checklist of 60,000+mile list.

So far I've changed the oil, oil filter, air filter, cleaned the t-body, changed the diff fluids, t-case, cleaned the MAF *mistake*, seafoam in the tank (soon to run through vacuum tube). And have loved every step.

Maybe a dumb question, but are you running premium fuel?

The PO of my truck didn't run premium so the SES was on when I bought it. After 2 tanks of premium (one with Seafoam) an induction and throttle body cleaning my SES light went off. I had a coupe of the codes you had and they disappeared after putting in good gas and Seafoaming.

It sounds like your situation might be a little more serious, but it never hurts to start simple and work your way up to the more complex. I'd say once you get done with the induction cleaning, swap out your plugs and wires (yes go with 8mm, that is the only thing people on this forum agree on:D).... and see what happens.

Congrats on the "new" Rover by the way and welcome!

First off, not a dumb question for a newbie, but yes I'm running premium. I'm going through my 2nd tank now which has the seafoam in it, and i'll do the induction cleaning tonight. I've been advised to go plug and wires first, new front o2 sensors 2nd, and go from there. So i'm ordering the bosch +4's and magnecor 8mm's now from BP utah (formerly rover connection).

For both sets its 190+shipping...anyone know of any better?

Thanks for the welcome and the advice!

Good stuff, get ready for some smoke and some possibly angry neighbors! Do you have a good idea how to do it?

I got my 8mm Magnecors online from Apex Performance (LRF recommended) and they were around $90, got my +4 plugs were around $5 Each from Rock Auto.

No matter where you get your plugs, here's a link to a rebate from from Bosch to get a little money back.

http://www.boschautoparts.com/promot...lugRebate.aspx

I have done the ol' seafoam once before on my old jeep, and i've got a very helpful LR enthusiast for a bro-in-law...otherwise I'd be dumbfounded for the most part (besides the premium fuel thing! lol)

Thanks for the referral companies, i'm gonna check them out right now...and my neighbors will be fine, they are either too old to see the smoke, or too white trash to even notice.

yes apexperformance is the spot for Magnecors. just make sure you get the 8mm's and plugs you can get anywhere i got my on amazon. once you get new wires and plugs you might clear some of those codes but until if your HG's are shot then you will still read misfires.

Well I just lined up my HG's job for next wednesday along with all the other gaskets...and while they are out I'm gonna have the heads resurfaced and valves checked and pressurized etc. I found a local previous LR dealer mechanic that is quite cost-effective.

I now have plugs and wires on the way along with front o2 sensors.

Thanks again.

there is a write up in the tech section on changing the wires without removing the intake manifold. make sure to read that and print the diagram so you don't cross wires when swapping the old ones out for the new.

Yes, I have read through all of the how-to and tech articles (at least once) and will definitely be printing out the diagram before undertaking the wires.

Thanks.

Updates!!!!!!!
 

Down from 13 codes to 5, and I'm narrowing in on the last five!!

Codes now gone: 0135, 0155, 1300, 0306, 0305, 0300, 0303, 0308
Current codes: 0134, 0154, 0141, 0161, 0160

Here's what I've done to date, most of it preventative maintenance:

Gaskets - heads, intake manifold, valve, t-body deicer
Heads machined
Valve job
Serp belt
T/stat
Prestone coolant
Oil change
Oil filter
Air filter
T-body cleaned
Bosch plat +4's
Magnecor 8mm's
Diff fluids
T/case fluid (need to re-seal soon)
ATF fluid & filter
o2 sensors (front 2)

After the gasket job I was running the cylinder misfire codes because I cleaned the MAF sensor *ROOKIE MISTAKE*. Once I got the new MAF sensor & intake hose (mine was ripped) I dropped all codes except the current 5. I've been doing other maintenance stuff such as fluids while I waited to buy the 02 sensors.

I ordered the front 2 o2 sensors from Atlantic British and installed them. Nadda change, same codes. Called them up and told them to send me all 4 and I'll mail back the first front o2's.

While installing the front o2's this weekend I noticed that I missing 2 out of 3 nuts on the drivers side underneath where the y-pipe connects to the exhaust manifold!!!!! (missing another nut on the passengers side too) I'm guessing there is enough gap between the manifold & y-pipe to cause my codes even with good o2 sensors!?!? Anyone know off-hand what size nut I'm looking for to fit these threads? I will post pictures up tonight, but should I be able to just tighten the new nuts on? 1 of the 2 threads without nuts is flush with the y-pipe but I figure if I tighten the other one, it will decrease the gap and give me room to tighten the last one on?

So, aside from the post-cat drivers o2 that I can't get off even after PB blasting the hell out of it (if a longer wrench doesn't work, I'll try heating it up?), I figure I need to find the right size nuts first to give these new o2's a chance at success.

Also, anyone have a picture of where their post-cat o2 sensor clips connect? Mine seem to either be stuffed up out of the way or hanging.

Lastly, my SLS has been acting up to boot. I'm following another thread where the guy is having the same exact issue as me - every other day or so it randomly deflates while driving, but after turning car off for an hour or two it will re-inflate. Hopefully a cheap fix as I'd rather not convert to coils yet.

Thanks for reading and for any helpful advice or tips!

yes that leak is causing your codes. do you have the rave manual? http://www.landroverresource.com/rave.zip

Yes I have it, thank you. As of yet, I haven't been able to find what size hex nuts these are. I'm sure I can always check the 1 or 2 that are still there later tonight.

Updates
 

I hate reading posts when someone had the same problems that I'm having, only for them to not report back with what their remedy was...so I'm reporting back so I don't kick my own ass!

All (4) new o2 sensors and that took care of my rear o2 codes (0160, 0161, and 0141). Just down to P0134 and P0154 (front o2's no activity). I've gone through 2 replacement sets of front o2's from AB and still have these.
I'm going to try and clean the connections one more time and use some dialectric grease on the connections and see if I can't get some activity out of these. I have had a slight oil leak that seems to get sprayed back, i'm guessing both crank seals could be replaced, but I think it started when I went to mobil 1 5w-30, so I'll see if the Rotella slows it up before I get the seals done. The connectors don't seem to have much or any oil on them, but its possibly the culprit.

I've also run a can of 44k through the tank and just changed the oil(rotella shout-out) and filter (mobil301) and tossed in some BG MOA into the oil. The car runs smooth, very strong and the throttle response is fantastic...but it is running very rich still and I don't know what else would be causing this then the front o2's not reading at all or properly. Quite a bit of water and some black stuff comes out of the exhaust when revved quite a bit.
That's it for now!

ever get those codes cleared? If so, what did you end up doing?

Hah, no. Actually, I'm just writing up a new thread now to try and solve this problem. It will be titled "electrical geeks unite".