Hi,
I have 2002 dodge caravan with the 3.3l. I've been lossing power with major fuel mileage loss atleast 50% I've take my van into 2 seperate shop both had different answers, neither fixed it. Blows black smoke from exhuast, idles rough, stalls some times, got to the point where it hardly runs at all. Untill last week there was no check engine light. When it come on I scanned it gave a P0173 code ( lean condition bank 1) Check all the plugs and they look like they have 150,000 miles on them, But I put new plugs and coil in November, my van only has 64,000 miles on it. this model does have the egr valve on it, but no code. I've always changed the oil on time, use injector cleaner monthly. I realy don't want to take it to someone else, I've spent enough for nothing. If anyone has a thought I would love to hear from you, thanks for your time.
Josh

 

I don't know to much about it, but! If is it black smoke it looks more like burning gas, not oil. Oil smoke is more like light blue smoke. So, Could be one of these sensors (I guess! try it) : Throttle position sensor (check the income air to make the mix with gas)

Try it!

 

You can check the Oxygen Sensor.

 

I'm sure the air filter has been changed. The air inlet to the filter has not in some way gotten blocked. Sounds like it's choking out.
Once it starts showing a Lean running eng. it will than run rich. Fuel psi ok? One or more injector leaking?A bad injector sould cause a misfire, that you don't show. O2 a good ideal and they don't always show a code. CTS not with in range. MAP will cause a rough and rich running Eng. Now what is causing the lean code? Fuel psi.,Fuel filter.

 

Forgot the EGR. If it is not seating and causing Ex. back into the intake, it will run real rough and should stall. When at idle if you apply vaccum at the valve to open the eng. should stall. The egr valve should hold a vaccum sorce. Pitle on the egr could be stuck open some what . The egr solenoid could be at fault. A bad EGR would cause a lean and dirty eng. Thinking about the spark plugs.

 

Checked MAP sensor today, Sensor had bad ground and MAP itself would not respond, so I order new MAP and plugs. I also tested the engine air temp the thing in the boot before manifold and thats working properly. Then I run out of daylight. So tommorrow I plan to check EGR valve and time permiting 02 sensors. But at this point I think the MAP is the problem. What do you think? I quess it very well could be a bad injector idk. Thanks Josh

 

If I pull the vaccum line off of the map the Eng. will run really bad. Hows does your's act? Yes a bad map will cause it to run all over the place. With map vaccum removed,no way could it be driven.

 

MAP sensor bolts directly to manifold so I can't pull a vaccum line. Here in about an hour I will be getting my parts so I will update Friday as to the outcome. At this point van won't even start. I will be changing the oil, MAP sensor, plugs, and air filter tonight. If you can think of anything else, I would greatly appreciate it. Thanks.
Josh

 

Ok I've been misled by my own doing. I first checked the MAP sensor and found a bad ground, so i fixed that, power tested good then retested ground and that was good. But never rechecked the signal wire. So I ordered the MAP and put it in, then tested the signal wire, which still has no signal. FYI signal wire is dark blue with dark green stripe. When I looked for that wire on the ecu I found two wires that look quite a bit alike. Tested the first one and nothing coming out. tested the second one which I am beigning to think is not the correct wire and that has ohm's coming out. I tested these with ignition off. So if the first wire tested is the MAP signal wire what do I check next???????????????????????????????????? Would that mean a possible wiring clip problem or do I need to replace the $850 ECU???? IDK................. Thanks, Josh

Bye the way I just wanted to thank BNTune for all your input, I'm checking all possibilities, now iI don't know where to start.