P0171 and P0303

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
Sorry to hear that brother. Sucks big time.
 

thebat

Original poster
Member
May 14, 2017
79
New England
Couple more questions. My live data shows ETC about 190F but the temp gauge shows slightly higher then 210. Does this mean there is a problem with thermostat or sensor? This is consistent reading after warm up and highway driving about 65 MPH.
Another thing, keeping in mind that my 05 TB, 4.2L, needs a valve job (low compression on #3), I get 66MPH on level highway with tach at 2K. I have the GU4, 3.08 gear. What MPH will a great running TB do at 2K RPM?
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
I've never one with the 3.08. Usual is 3.42 and 3.73. Some have 4.10 but mostly SS. You got your code from the glove box?

Gearing RPO codes
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
I get 66MPH on level highway with tach at 2K. I have the GU4, 3.08 gear. What MPH will a great running TB do at 2K RPM?

You basically answered your own question.
 

thebat

Original poster
Member
May 14, 2017
79
New England
So 66MPH @ 2000RPM is good?

I'm pulling the valve cover next week and am scheduled for valve job. if it needs it. I'm trying to get a feel for what else I should do if full valve job is needed. That's why I asked about temperatures.. I could put in new thermostat if necessary. I am going to change serpentine belt and upstream O2 sensor. Anything else I should do?
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
Just a forewarning that a head job on these ALWAYS result in broken head and exhaust bolts. And you also absolutely need a wedge tool to hold the timing chain tensioned otherwise you will have to pull the oil pan. Most opt to just replace the entire engine.

You should do a leakdown test to confirm where you are losing compression.
 
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thebat

Original poster
Member
May 14, 2017
79
New England
Thanks Mooseman, I am having it done at local shop, these guys are good, highly recommended. They are doing compression test then looking at valves before they open engine up. I will be over there when they do this.
I do not have the skills to do this job so I'm relying on them.
Any thoughts on other parts I should replace? Right now I'm doing serpentine belt, upstream 02, tube that supplies vacuum to rear HVAC. If you can think of any other common problem parts to do while engine is accessible let me know.
 

5xBuckman

Member
May 10, 2017
28
Minneapolis
Thanks for all the information contained on this site. I really appreciate the advice about removing the motor mounts and lowering the tail of the transmission to gain access to the 2 top bellhousing bolts. Taking apart the various double lock electrical connections is a time consuming task.

I'm one to replace various thing while I have good access. So I installed a new water pump, thermostat, upstream O2. Then I dumped the transmission fluid, installed a new filter, changed the power steering fluid.

The CAT was iffy, so it got a new one.

It's a tedious swap to be sure.

Last question. I had to remove the radiator and open the AC to gain access through the grill to R&R the engine. So, I gather I will need a new accumulator, apply some vacuum prior to recharging the AC....but how much PAG 46 oil should I add?

Thanks
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
:offtopic: but I'll answer anyway. If replacing just the accumulator/dryer, it should take 2oz. (6ml) of oil. That's what I just put in to replace mine.
 

thebat

Original poster
Member
May 14, 2017
79
New England
So, I got the valve job. The truck now runs great and there is:

No more rough idle. Now, when engine is warm, TB idles at 600RPM all the time, no more bouncing around or stall.

No more cruise control problem. It would fail intermittently by refusing to turn on. After restart CC was okay for a couple of days, then refuse to turn on. Restart, OK, then fail again. Very annoying. Also, it was choppy when going downhill with CC on. After valve job, it is just like new.

MPGs have soared. The best I would get on highway was about 17 MPG. Now, I'm getting over 23 Highway and over 14 city. I LOVE IT!

So I'm glad I went for the money and thanks to everyone whose advice was helpful. I really appreciate it.
 
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