xjallseasons

From a start I will give it gas and it will bog down like I am down a gear but its an automatic and it hasn't down shifted at all. Eventually it will stop doing that and go back to normal. It doesn't last long maybe 100 feet. If I give it more gas it'll just sputter. It almost feels like the exhaust has a clog, but it doesn't do it all the time maybe 1 time in 15 starts maybe less maybe more as I really don't keep track. Another poster on this has said that his changing out the injectors to 4 hole causes his to do the same, but I have not changed mine (they might be OEM).

xjallseasons

The other thing it does is make a loud pop, almost like a backfire but its in the engine bay and I don't think anyone but me can hear it.

IJM

Does the problem go away at full throttle?

Rogue4x4

Running a cat? Maybe it's plugged or broken, busted honeycomb could get erratic

xjallseasons

It does have a cat. Is the honeycomb the protective metal with all the holes? If you mean like its loose then I don't hear clunking or anything loose. Plugged or broken it could be.

I haven't given it gas at full throttle when it happens. I guess I am too worried I may not be able to slow it down because when it happens, I am usually in a neighborhood.

Rogue4x4

Broken won't always mean loose and rattling, it might be a section that has separated and shifted enough to move slightly, blocking the flow. Heat and vibration can make it intermittent. Any codes thrown for rich or lean conditions, or 02 sensors? Have you looked underneath when it occurs? Any glowing red pipes?

If no, you might want to try removing the exhaust from the cat back, run it, and see if it changes.

cruiser54

You can test for exhaust restriction.

Popping through the intake can be an indication of low fuel delivery/pressure. CRUISER'S MOSTLY RENIX TIPS

VACUUM TEST FOR EXHAUST RESTRICTION

OCTOBER 31, 2015 SALAD 3 COMMENTS

Your vacuum gauge should come with an instruction booklet outlining the procedure.

Hook the gauge up to a vacuum source on the intake manifold. Start the engine and note the vacuum reading. Usually 17 to 21 inches of vacuum.

Throttle the engine up to 2,000 to 2,500 RPM for 20 seconds or so and the vacuum reading should stabilize to the same reading you got at idle.

Let the throttle snap shut. The vacuum reading should shoot up about 5 inches of vacuum higher for a second and then come quickly down to the original reading. If the vacuum reading stays high and comes down slowly with jerky needle movements, you have an exhaust restriction.

robsjeep

honey comb is made of a ceramic material. it contains the catalyst on its surface. the catalyst is metals that are fantastically valuable, that combined with liberal soft on crime policies have led to a large number of thefts of catalysts..

Rogue4x4

robsjeep

If only our catalysts honeycombs were populated with swams of poison wasps. Sting the catalyst thieves to death!
California lefties are soft on crime, yet they dont seem to be mad when soft on crime policies result in the destruction of pollution control devices, nor cause huge economic hardships for the working class that they claim to care about. California is nuts politically speaking.

TheNoticer

Do a fuel pressure test, could easily be fuel pump and can borrow the fuel pressure tester from AutoZone with deposit. Need to observe fuel pressure when started, while running, when shut off, and also while driving (can be tricky to observe when driving I mounted a camera in engine bay).

If you lose like 10 psi or more in 30 seconds after shutting off that's a good indicator. The final determining factor was when driving down the road when opened up full throttle my fuel pressure dove way down that's when I was certain it was fuel pump.

xjallseasons

There aren't any loose pieces of metal that I can see from the outside. The exhaust is covered in mud and has always been that way, so I have never noticed glowing hot pipes. I have replaced the exhaust manifold because of the issues of the OEM ones cracking. I sent mine to get Jet Hot treated to keep the temps low. From there I have not replaced any thing else. I have a friend who is also a mechanic that has 8 XJ's and I could possibly get a catalytic converter from him. If mine has broken apart then replacing it may help out.

xjallseasons

I haven't even thought of running this test or even heard of it. It seems quick extensive and something I should bring up to my mechanic. Thanks.

xjallseasons

Our governor has implemented a law for the theft of these.PHOENIX — The Arizona Legislature has successfully passed a bill that attempts to curb the state's rising number of catalytic converter thefts observed throughout the Valley.

House Bill 2652 adds a number of provisions to Arizona law that are intended to help law enforcement keep track of catalytic converters illegally stolen and sold on the black market.

xjallseasons

This too is another test I have not even heard of. Wow, my cherokee has so many issues... is it even worth fixing? It runs great, has no codes and is fun to drive. Could the possible clog in the converter cause it to run badly and not help me get better mpg's? I did replace my MAP sensor and soon will replace the IACV and TPS. Meanwhile my a/c isn't working properly because of the brown connector to the adjustment for air. Then I have to replace my steering wheel, clock spring and ignition switch box. My vacuum hoses are shot and so are the elbows they connect. I need a new gas tank since mine has a dent on both sides. I know I am losing how much fuel I can carry.