So I am getting a rough idle and a heavy gas smell around the car. It is also giving a code p0174. Bank two lean. I can't find a single gas leak. I have not done the smoke test but I visually inspected everything. I just gave it a new fuel filter, it has not been replaced in a really long time. I near as I can tell the o2 sensors are giving a good reading on the code reader.


Does anyone have any thoughts? Thanks


-2001 WJ 4.7

 

Air intake leaks - could be vacuum or actual gasket - check vacuum lines first - check all of them even on the evap system
Faulty O2 sensor
Mass Air Flow sensor (if you have one, I don't remember if that model does)
Ignition misfire - likely not without a misfire code however, the smell of fuel could be an indication of unburned fuel entering the cat due to a bad injection and pcm is not picking up yet as a misfire
Incorrect fuel pressure

Is the smell of fuel, like raw fuel as though it was coming out of the tank or a gas pump? Or is it fuel smell like it's only partially burned through the exhaust?

 

It does not smell quite like I am at a gas station. So I would say more so spent fuel. I can smell fuel out of the tailpipe, but it seems to me a bit stronger on the drivers side when you just standing next to it. Weird..

I don't have a miss fire code. I would be surprised though, if something was up as the plugs and cap/rotor were replaced last summer.

 

Bank 2 is passenger side, if I remember correctly. A bit unusual to have stronger smell on on drivers side. Do you have a fuel leak in a line? Could be causing a fuel pressure issue. TP sensor maybe, exhaust manifold gasket perhaps.........start digging in. The fuel trim codes can be some of the more tricky ones to diagnose. Many folks have a lean code and engine runs fine, only a slight reduction in mpg. In your case, with the rough idle and fuel smell, there is def. a problem.

 

I just noticed that i am getting a lite amount of black smoke out of the tail pipe. Nothing like a diesel or anything. But it is noticeable. I read that if you go up to 35mph and coast down to 15mph 10+ times it should through a misfire code. If that is a problem. Cause i am reading that a system lean code can be a symptom of a misfire. But i have done it a few times and could not get a code.

 

I have the same problem right. Now some said that is misfiring. Other said it could be a clog injector. My I ask what would be my first step to determine the problem.

 

So I am thinking it is the fuel pressure regulator/fuel pump. As the fuel pressure is 10psi higher then the Max that it should be. Fixing it now, will post an update.

 

Will also check mine... Finger cross I hope its just a simple fuel regulator or pump.

 

I replaced it, it did not fix the issue. We noticed that the spark plugs are really dirty though that were replaced like 10 months ago.

Dang...

 

What time of plugs are you using? Will iridium plugs would help at all?

 

Not sure, if they would in my case. None the less though we took out everything. The o2 sensors, spark plugs and all and clean them. Did a fuel system cleaning and all is now well. Problem seems to be fixed.

 

Glad to hear you've fixed the problem. These Jeeps seem to have very sensitive fuel systems! Make sure you clear out that code so you can see if it comes back in a few weeks.

 

If that's the case, that means the clog could be removed from somewhere.