New Mexico Roll Call.
Member
Joined: Jan 2013
Posts: 231
Likes: 0
From: Albuquerque, NM
Year: 1998
Model: Cherokee
Engine: 4.0 I6
My jeep is getting an average of 13-14 mpgs. Last month I installed new plugs, wires, cap, rotor, front o2 sensor, air filter, and fresh oil. My stock exhaust has seen its better days. I'm thinking my cat is clogged and its killing my mpgs. How can you tell if the cat is bad?
Member
Joined: Feb 2013
Posts: 135
Likes: 0
From: albuquerque
Year: 1997
Model: Cherokee
Engine: 4.0L
Put your hand over the exhaust tip if you can feel a lot of air your ok if you feel only a little. It's clogged. But if it is clogged you will run hot an have no power also. I don't think there is a true way to really check if its bad other than if its obd2 an its throwin codes. But I could be wrong.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
My jeep is getting an average of 13-14 mpgs. Last month I installed new plugs, wires, cap, rotor, front o2 sensor, air filter, and fresh oil. My stock exhaust has seen its better days. I'm thinking my cat is clogged and its killing my mpgs. How can you tell if the cat is bad?
Your vacuum gauge should come with an instruction booklet outlining the procedure. Hook the vacuum gauge up to a 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.
CF Veteran
Joined: Mar 2012
Posts: 3,404
Likes: 1
From: Albuquerque, NM
Year: 1995
Model: Cherokee
Engine: 4.0
CRUISER’S VACUUM TEST FOR EXHAUST RESTRICTION
Your vacuum gauge should come with an instruction booklet outlining the procedure. Hook the vacuum gauge up to a 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.
Your vacuum gauge should come with an instruction booklet outlining the procedure. Hook the vacuum gauge up to a 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.
Cruiser you need to just write a jeep manual for how much you help in the tech threads
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Click on the "pink link" in my signature. Most of it's there.
A vacuum gauge is an incredible and incredibly cheap diagnostic tool. You can even mount one permanently in your dash to help you drive economically.
http://www.ehow.com/how_8098066_driv...-gasoline.html
Junior Member
Joined: Nov 2010
Posts: 37
Likes: 0
From: Albuquerque NM
Year: 1989
Model: Cherokee
Engine: 4.0
There is a really good place on 3rd street north of down town. They just did a fender repair for one of my friends, the paint is perfect match to the rest of the vehicle. They were also less $$$ than the other places be checked. I will get and post the name and address for you tomorrow.
Seasoned Member
Joined: Apr 2012
Posts: 279
Likes: 0
From: Albuquerque NM
Year: 1993
Model: Cherokee
Engine: 4.0HO
Whats up everyone. Havent been on here in a while. Havent done much to the jeep either. Its just sitting looking purdy right now. Need to take her out and get her dirty but havent had the time with getting a new bow and always going to shoot that and all. I see some new people on here that i havent seen before.
Junior Member
Joined: Feb 2010
Posts: 49
Likes: 0
From: Albuquerque, NM
Year: 1992
Model: Cherokee
Engine: 4.0l
There is a really good place on 3rd street north of down town. They just did a fender repair for one of my friends, the paint is perfect match to the rest of the vehicle. They were also less $$$ than the other places be checked. I will get and post the name and address for you tomorrow.