kirtondog23

I am still working through my bank 2 lean code. I had my computer reprogrammed and now the code still comes on and I can still smell gas as I drive but at least my exhaust is not burning up my floorboards.

I have had current performance program the computer twice now and am getting tired of pulling my computer and sending it to florida.

I finally found a place that will do dyno tunes in my area. I am thinking I should just pony up the dough and get it tuned for my conditions with someone in person to make this thing run right. My 6.0L is running so poorly that I am getting 8.3 miles to the gallon and sounds more like a lawn mower. I was driving like a granny too.

My fuel pressure is at 55 psi as I mentioned before and I am going through some tests to figure out the best way to fix that.

With the conditions that I have described am I thinking right about getting a retune in person?

Kamin

this is a very stupid question, have you swapped o2 sensors (side to side) to see if the code follows the o2?

people immediately jump to a computer/tune problem without actually troubleshooting anything a lot of the time.

kirtondog23

It is actually a very good question. I have had the engine checked very carefully at an engine tuning place and the sensors checked out. That was my first guess as to what might have been wrong when this whole gaga began a few months back.

as for an update I rechecked my fuel pressure and it is more like 56.5 psi and does not jump higher when I connect it right to my battery. The weird thing is that when I pulled the fuel pressure dial of the motor and put the plug back in the fuel rail and drove the truck home the check engine light went off and I am smelling less gas. I'll be monitoring it further but maybe this plug was not in tight before and I was losing fuel before it even got to the engine, which could explain the lean code and extreeme fuel consumption as well as the gas smell.

Lets ses if I get lucky. Anyone think my theory might be right or might I be missing something?

dmc454

My 2 cents say that you may have a vacume leak.The o2 on that side is seeing more air to it and may be pulsing the injectors more on that side.If you have a scan tool you can check your ltft & stft to see if it is making the injectors work more.Also you need to check for a leaking injector this would cause this also.To check with a scan tool look at the stft as you spray a small amount of carb cleaner near any vacume source.I would check around any fitting on the intake and were it meets the heads. Im in tech school and this was a problem the instructor bugged the car with.The tune had nothing to do with the problem.Hope this helps

kirtondog23

Thanks for the response. Just for clarification.. on my 2004 6.0 there are only two sources of vacuum possible on the engine the drivers side rear where the vacuum line runs to the master cylinder and that little nipple about half way back on the massager side of the intake manifold if I snipped the end off. Are there any others that I need to check?

Also I had Tunnex put the smoker on the engine and they "say" they could bot find any intake or exhaust leaks. ( They did find one exhaust leak but it was after the sensor.) could they have overlook something or would a vacuum leak be pretty apparent with a smoker?

Thanks

01WS6/tamu

iTrader: (37)

Check to make sure that the exhaust shop used an 02 bung and not a nut welded into the exhaust pipe. If they used a nut chances are the 02 is not immersed into the exhaust stream sufficiently and is seeing a lean condition and commanding more fuel to compensate. Which would cause poor gas mileage and lousy power. Also make sure they are within a eight to twelve inches of the exhaust manifold or header collector and installed between nine and three o' clock positions.

kirtondog23

My lean bank is 2. If I am informed correctly this should be the drivers side of the truck. In this case the exhaust shop modified the original exhaust pipe from the donor truck and so the bung has not been modified from it's stock arrangement. On the other hand the passenger side bung was made by the shop and is sitting at the three o'clock position.

Am I correct in terms of orientation?

01WS6/tamu

iTrader: (37)

Bank one is the drivers side bank 2 is the passenger side.

kirtondog23

Then I need to check the bung. If it was a nut they welded on it would be hexogonal and if a bung it would be round. It that right?

Thanks

kirtondog23

Update. the bung on the passenger side seems to be very similar to the bung on the drivers side.

There is a nipple on the top of my truck intake near the throttle body with an electrical plug and what looks like something similar to a bike tire nozzle. I am assuming this "unit" went to the emissions stuff like the evap canister. Is it possible that I could be getting a vacuum leak or otherwise getting air though this thingy? I was thinking about putting a vacuum cap over the nipple that is just exposed.

Thanks

01WS6/tamu

iTrader: (37)

If you are not using evap just unplug the electrical connector or put a cap on it for added safety it could do it. But it would have to be a 100percent open before it would start screwing up your fuel trims to the level that you are experiencing.

kirtondog23

It is already unplugged and has been the whole time. It sounds like capping the evap stuff isn't going to solve my problem

01WS6/tamu

iTrader: (37)

There are only three things that can cause a lean. vaccum leak use some carb cleaner around the intake allover the place and listen for a change in idle quality or speed if it does then it is a leak, restricted injectors run a drop test on them, 02 sensor arrangement leaning heavily towards this had this same problem on one of my conversions and or bad o2 stuck lean.

kirtondog23

I swapped the o2 sensors and finally got to drive the truck today and sure enough bank 2 is lean so the sensors are both good. I also sprayed the intake like crazy with no noticeable difference in the truck running. I have never done anything with injectors before, (prior engines were all older and never had an injector problem. How do you perform the drop test?

Also anything else I should be checking in the exhaust end? The bungs look similar (from the outside and are at the 3 and 9 position) but the passenger side is the new bung and pipe. Tunnex smoked it and found a leak behind the o2 but not in front.

Thanks