Chugging on 96 XLT 5.0

[96 Explorer]

I have had a "chugging" issue for some time and just replaced the left exhaust manifold and put in a new A/C unit-just got it back yesterday. Its going back to the shop later in the week but still wondering where the chugging is coming from. The chugging happens generally under 40mph and I know its not a leak. With the A/C on, Im getting more chugging at lower RPM's and wondering if anyone experienced the same. Its almost a like a spudder when taking off-not all the time but I notice it easily, especially when the A/C is on when beginning to accelerate.

So with the A/C on, more spuddering in the beginning of accelerating and the chugging under 40mph with the AC off.

Sensors are fine but wondering if it would be a vacuum hose or something??

Any insight would be great.

 

[Turdle]

It is usually the passenger side (right) manifold with the leaking (cracking) issue. Do you have the type of exhaust manifold with heat shield on it?

 

[96 Explorer]

The manifold was just replaced yesterday. The old one had a crack in it and not sure if it the new has a heat shield-my assumption is yes but will check.

 

[Turdle]

I would assume if the driver side cracked, the passenger side did also.
Another thing to look for, maybe a broken or loose spark plug. If exhuast manifolds are changed, spark plugs should be also.

 

[96 Explorer]

Nope, just one cracked. The perfomance is much better since the fix but it boils down to the chugging.

I'll check the plugs.