Guess I got lucky mine didn't break. I took them apart at the flange to put in new flange gaskets but didn't think to take it off at the other end to pour any antifreeze out. I did have one stud missing and ordered a replacement from rovahfarm or somewhere...don't remember. Luckily it wasn't broke off just missing completely.

02 sensors are supposed to be here tomorrow, can't wait to see if that fixes the problem. still getting 0150 code. no other codes now though. Fuel trim is totally screwed on bank 2 reading 25.00 long and short.

 

I put in the 2 front 02's today (bosch black box) and idles much smoother and so far no codes. Was getting 0150 every time I would clear it it would come back shortly after. It's not doing that now. I have only ran it about 30 minutes but, plan to go fill up and take it for a drive later today.

My front sensors are cycling according to UG up and down from 0.00 up to 7.00 or about and back to 0.00.

But my rear 02's started at .445 this morning and now bank 1 sensor 2 is staying around .150 and bank 2 sensor 2 is going way up to .665 or around. The are sitting pretty constant but numbers don't look right. I plan to order rear 02's today and install them in a few days.

Also my fuel trim is still not right. I may have to drive it more?

srt trim bank 2 is going from -12.5,-14.2,-17.2,-11.7,-16.6,-12.5,-14.8 and around.
long trim bank 2 is +24.22 but may need to go through some drive cycles to let the long trim adjust itself?

It's better than it was before. Both srt and lng on bank 2 were sitting at +25.00 before and it idles much better now. really can't feel anything odd when idling so far. sits at around 600 to 650 rpm idling in gear.

srt trim bank 1 is -.78, +0.78, +0.00, -1.6, -3.9
long trim bank 1 is 0.00

It is staying in closed loop most of the time at least.

anyway, not sure what all the fuel trim numbers are trying to tell me?
Anybody that can read these numbers and give any input would be greatly appreciated.
Thanks guys!

 

Ok since my ltft on bank 2 is still at +25 from the bad 02 sensors and stft is now at -14 or so instead of +25 like it was before the 02 sensor replacement, it is trying to correct itself I guess.

Can I disconnect the battery for an amount of time for it to clear it's learned settings and start fresh since I just put in the new front two 02 sensors or should I let it relearn on it's on and see how my numbers change?

Don't know how many miles it takes to relearn but, I've noticed the ltft is slow about coming down. Does it have to go through so many drive cycles from cold or so many miles or what? if it's 500 miles it may take me forever to get to that.

thanks for any help.

 

Maybe I'm asking too many questions.

So let me ask just one question.

If I disconnect my battery for 20 or 30 minutes will it reset my long term fuel trim base line back to zero?

thanks for any help.

 

Ok, I went ahead and disconnected my battery for an hour, reconnected it and it DID NOT reset the LTFT base line. So I guess the computer will have to adjust it back to zero base line on it's on.

When running it today the LTFT on bank 2 did finally start dropping and is now down to positive +11.72 down from +25.00 so that's a good sign.

STFT on bank 2 is running at lower numbers also, being now from 0 to negative -12.00 or around depending on RPM, so it's trying to stay opposite of the LTFT with LTFT in positive and STFT in negative.

Maybe It'll straighten itself out. Both front sensors are new bosch black box and now waiting on rear to be delivered.

I do not understand why the bank 1 rear sensor is running around .150 or so and the bank 2 rear sensor is running up near 7 or 800?

I hope it's not my cats? I am not getting any bad cat codes. Haven't had any codes pending or set since I replaced my front 02's but haven't driven many miles.

I guess I'm probably just worrying too much and need to relax and let the computer do it's thing on getting everything back to correct base lines. I'm used to seeing the LTFT adjust itself in other vehicles very quickly when the problem is fixed, but maybe these just take longer?

Also another thing this morning I had to crank the engine for a second or two before it started. Usually, or before I did the head gaskets, it would start immediately when you barely turned the engine over. Maybe I have an injector leak or something?

If it doesn't straighten out soon, I guess I'll try to check my fuel pressure. I know my timing is correct I checked it like three times before putting the front cover back on. Plus it runs good.

 

Everything is doing better now. LTFT on bank 2 is now down to +3.12 so, seems like it's dropping more each time I drive it.
I really didn't need bank 1 front 02 sensor but, everybody here says change them in pairs so I did. I'll just keep the old good one for testing if I ever have another 02 issue. Mine had 150k so I'm figuring by changing them both I may get better mileage?
Went about 20 miles today and no codes. knock on wood!

 

Rear O2 sensors don't cycle.
They are looking for the efficiency of the catalytic convertor only.

Those will go from around .1 when you are coasting up to about
.345volts under load.

You can only get an accurate reading up a huge hill on the rear o2's.

 

I would not worry about fuel trim.
I used to worry bout it with my D1 - but it did not do me any good

As long as your front O2 sensors are new you are set.

Rear O2 sensors dont' affect anything.
Rear O2 sensors are just used to tell if your catalytic convertor is shot or in good working order. That's all they do.

If the cat convertors are not scrubbing out unburned gasses, the
rear O2 sensors "notice" and you get a catalyst below efficiency or some warning like that.

I wrote this all up years ago in

http://jeffreyfall.com/landrover

best....

 

You can also pop codes into

http://enginecodemaster.com

Put in like a P and the code

Like P0150 or such.

Site was down but I fixed it.

 

Thanks for the links

Yep I used the P0150 code to determine I needed a new front 02 sensor on bank 2. went ahead and replaced both and that's when I started wondering why my long term fuel trip was still screwed up. I thought that it would reset itself faster.

I was just worried I may still have problems other than the 02 sensor. Long term has zeroed now on both banks so, everything is back to normal.

I know the rears don't cycle but, was wondering why one rear would read .150 and the other read .600 to .800? seems odd that they would be so far apart. was thinking it may be trying to tell me something about my cats. No cat codes at all though.

I topped the tank up today and made a few more trips and no codes or pending codes of any kind for now and LTFT staying at zero so I can quit obsessing over that!

Hopefully I can put this to rest now. I have always looked at fuel trims to help diagnose problems and guess land rover computers just don't work as fast as some. Took a full day and half of another for it to come back down to zero. Some come back down to zero in 30 minutes or less of drive time after a problem is fixed, never seen anything take a day or two.

I'm probably a little too obsessive and impatient. I normally don't watch all of my numbers so closely but since I just did the head gaskets I guess I was keeping an eye on everything a little too much.

anyway, thanks for the help. Now maybe I can move on to other things like new seals under my brake reservoir and front hubs.