So I've read a past thread with symptoms is exactly like mine, but I did not see a final solution.
I have low compression in #6 and #5 but 5 is not showing up, other than that the truck runs good and on the open highway at 75 - 80 mph doesn't skip a beat. No oil usage, no oil leak, etc...
I can erase the code and as long as I am on the highway it doesn't code, stop and idle it codes.
Numbers from compression testing:
Dry 1-6 in order: 108-122-115-122-83-55
Wet 1-6 in order:110-125-121-129-100-50
Valves, head gasket between 5 & 6?, worn cam, lifters? Any thoughts?
I have run a flush in the oil, changed the oil and added Marvel. Has not been in long enough to say there is a difference yet.
196,000 Miles and I bought new, so one owner. My next thought would be to remove the valve cover to inspect and then remove the heads.
I this a waste of time? Should I just get a rebuilt engine?
Thanks!

 

Welcome to the forum

Overall pressure is low, but that would be the pressure gauge you used, because levels that low would cause a very noticeable lack of power

Your 3.0l Vulcan engine ran 9.3:1 compression ratio
General rule of thumb is to multiply compression ratio by 18 to get expected PSI on cold/dry test, 9.3 x 18 = 167.4psi

The dry then wet test shows its a valve issue, #5 and #6 exhaust valve are probably burnt and leaking, so heads will need to come off

2004 to 2006 3.0l Rangers did have exhaust valve issues, your 2002 so probably not the sane issue, but..................................

I don't see rebuilding bottom end at 200k miles, 400k may be


It possible head gasket between 5 and 6 is bad, but heads need to come off either way

 

Exhaust seats for sure... choice is to get your heads repaired, compare price between that and new and heads $450..... don't get rebuilt exchange heads.... been through it, see my post below

 

Thanks, I appreciate the advice. After looking at my options. If I was going to get rid of the truck I would probably just do the heads and I don't have the confidence to believe the bottom will last another 200,000 miles.
However since I bought it new and my son has been driving it the last seven years and wants to keep it "forever", he has decided that he is going to have the engine rebuilt at a local shop that has been doing this in Phoenix for forty two years. Hopefully he can drive it for years to come.
Thanks again!

 

So just update those that care or it might help.
The exhaust valves in #5, #6, and #3 are shot as comments above have been confirmed, thank you. They said that the heads are shot and he hasn't seen one recessed this bad in awhile and the only thing that can screw it up this much is back pressure on the exhaust. Bottom looks okay. Builder said that in no way should the rebuilt engine be connected to this exhaust. He said tow it straight to the muffler shop and have the exhaust taken care of.
Joy!
Any thoughts on cleaning the "cats", buying bolt on replacements, or having the exhaust modified at a muffler shop?

 

Anything done like that here in California would close the muffler shop down tampering/removing cats, i agree its overkill with two cats up front and three below plus three 02 sensors ...like on my 2003 ranger 3.0.... smog check every two years, smog stations do not inspect how many cats are on truck ..they only plug in scanner to the ECU 12 pin connector... no tail pipe emission check..