96 4.0 codes P0174,P0305,P0306
#1
96 4.0 codes P0174,P0305,P0306
96 4.0 codes
P0174 running rich/lean
P0305 cylinder 5 misfire
P0306 cylider 6 misfire
Runs rough, low power. My 19 yr old son (his truck) pulled the codes and I have him checking out the PCV valve and hose. Which O2 sensor throws the P0174? I'm in Iraq with my guard unit so I'm not home to walk him through this or look at the Chiltons, so I have to do it over the internet for him. Any suggestions? I can usually track this stuff down on my own but I don't have the vehicle in front of me.
Thanks.
P0174 running rich/lean
P0305 cylinder 5 misfire
P0306 cylider 6 misfire
Runs rough, low power. My 19 yr old son (his truck) pulled the codes and I have him checking out the PCV valve and hose. Which O2 sensor throws the P0174? I'm in Iraq with my guard unit so I'm not home to walk him through this or look at the Chiltons, so I have to do it over the internet for him. Any suggestions? I can usually track this stuff down on my own but I don't have the vehicle in front of me.
Thanks.
#2
#3
#5
You should have him do a fuel pressure test at the shrader valve (looks like a tire presure gauge) from memory I think it should about 40 and drop some when running. Have him pull off the vacumm line on the fuel presure regulalator. I think it is on the fuel rail. There should not be gas in the vacuum line.also He can look for a vacuum leak on the engine . Has there been any other work/maintanance done
#6
I have a fuel pressure guage in my shop. He's never used one before so I'll try to talk him though it. I'll get back to you. He did replace the fuel filter a few months ago on his own. The old filter actually popped out on its own so he put a new one in.
The truck has to have 200,000 miles on it by now. I bought it for him a couple of years ago and it had 140,000 when I got it. I tracked down two codes it was throwing back then and replaced two sensors and haven't had any problems since with the engine. It's been a good truck.
The truck has to have 200,000 miles on it by now. I bought it for him a couple of years ago and it had 140,000 when I got it. I tracked down two codes it was throwing back then and replaced two sensors and haven't had any problems since with the engine. It's been a good truck.
#7
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#8
Didn't do the fuel pressure test yet, but the vacume hose going into the fuel pressure regulator was removed and inspected. It is wet inside with fuel. Also the oil is thinned in the crankcase. I have him replacing the regulator and the oil/filter as well as the plugs. We will see if that takes care of business.
#10
Those codes are on two adjacent cylinders. It seems very likely to me that he may have a blown head gasket. Does he have to add coolant? Any bubbles in the radiator? How does the oil look? Misfires will often set lean codes, remember, the O2 sensor does not measure the air to fuel ratio, it only measures the amount of oxygen. If the fuel doesn't burn in the cylinder, then the O2 sensor will detect it and you get a lean code.
#11
Didn't do the fuel pressure test yet, but the vacume hose going into the fuel pressure regulator was removed and inspected. It is wet inside with fuel. Also the oil is thinned in the crankcase. I have him replacing the regulator and the oil/filter as well as the plugs. We will see if that takes care of business.
#12
#13
He changed the fuel pressure regulator and it still had loss of power and threw codes.
Here is what happened,
1- Truck was running poorly and getting progressively worse. Threw codes.
2- Son changed wires and plugs. Truck still ran poorly if not worse.
3- Son asks for my help via internet and tells me he scanned the codes with my scanner and he told me what they were.
4- With help via forum member 'powersmoked' he checks the regulator vacume tube and it was wet with fuel. Also the oil was 'thin' according to him, after I asked him to check it.
5- Changed regulator and still runs underpowered but with more power than before. Still running poorly.
6- I get message from home that he checked the plug wires and he had them in the wrong order.
7- I'm told it now runs great. No mention if the codes came back yet. Will find out tomorrow.
I need to ask if he changed the plugs and wires before the codes or after. I will let you know.
Edit-
8- The codes were there before he did the plugs and wires initially. Check Engine Light is no longer on and the codes have cleared.
SUCCESS!!!
Here is what happened,
1- Truck was running poorly and getting progressively worse. Threw codes.
2- Son changed wires and plugs. Truck still ran poorly if not worse.
3- Son asks for my help via internet and tells me he scanned the codes with my scanner and he told me what they were.
4- With help via forum member 'powersmoked' he checks the regulator vacume tube and it was wet with fuel. Also the oil was 'thin' according to him, after I asked him to check it.
5- Changed regulator and still runs underpowered but with more power than before. Still running poorly.
6- I get message from home that he checked the plug wires and he had them in the wrong order.
7- I'm told it now runs great. No mention if the codes came back yet. Will find out tomorrow.
I need to ask if he changed the plugs and wires before the codes or after. I will let you know.
Edit-
8- The codes were there before he did the plugs and wires initially. Check Engine Light is no longer on and the codes have cleared.
SUCCESS!!!