help! poping noise from the exhaust

[Ray Bone]

I have 95SW, just had a tune up and oil change, all geninue parts.
there is a poping nosie coming from the exhaust, underneath the gear, felt there is a pressure in the exhaust is not coming out, sometimes there is no pick up when i accelerating , and it jerks on the first and 2nd gear, it sound like the truck is farting everytime i switch gear and accelerating. I put a bottle of the land rover fuel injection cleaner and drove 40miles on the highway, motor ran strong and smooth.
Also I looked at the exhaust pipe, its black and smell like a gasoline.
Can anyone give me some idea? Fuel injection sensor? cat converter? O2 sensor? or what?
Thanks
Bone

[Mike Hippert]

Give all the spark plug wires a good push to make sure evrything is seated right. I'm not too clear on what you are saying, You had a tune up, it statred backfiring, then you ran injection cleaner in the gas and it ran good for 40 miles, then ??? it ran bad again? or good?

[Ray Bone]

sorry for the confusion
I mean i tried the fuel injection cleaner, ran about 40 miles, i don't think the problem came from the motor, I just double check the ignition wires and the rotor cap, everything is tight and firm.

[Mike Hippert]

OK so it's still not running too good, could they have bumped off one of the vacuum hoses? Specially the vacuum advance on the Distributor. Also make sure that the distributor is not loose, thus advancing or retarding the timing. And just to make sure I am clear, this all started after it was worked on.

[Ray Bone]

yes the vacuum hose was off, when I checked last week, i am pretty sure everything is as tight as it gets, but i will double check one more time.