engine running rough

have a 98 grand cherokee that recently started running real rough. have replaced rotor, cap, plugs and wires. also, changed rear pcv valve, but motor still running rough and at times loping when idling. any suggestions.......

Did it start running rough after changing the spark plug wires? A swapped wire can cause it to run rough, but mostly OK.

Is the miss only at low speeds or at all speeds? If only at low speeds, check for a vacuum leak. If all speeds, check for a bad injector or ignition issues.

It started before the tune up ..it was weird ran normal then started it up and it ran real ruff and had an exhaust leak in the manifold I fixed the leak and did the tune up and it is still the same / No lights came on on the dash but I am still going to see if I can get the codes pulled / It seems like it is running rich and missing Is there a way to check the tps/mapand other sensors with out a scanner ?