I guess I have an evap leak. My mechanic said the entire system has to be taken out. Does anyone have experience with evap problems?

 

"Well looks like you have a small trace oil leak, LOOKS LIKE WE NEED TO REMOVE THE ENTIRE SYSTEM"

Who says that?

Take it to a real mechanic. Unless 100% of all your lines, solenoids, canister are cracked and broken you do not need to take out 'the entire system'.

 

Do you have a code stored? Let's start there....

 

Pardon my thread resurrection and ignorance to evap, but how would i start diagnosing this? its probably the one part of the vehicle i know absolutely nothing about. and no i dont have the code stored. it just said evap leak

 

Start with the gas cap and look at the lines for cracking. There are also metal lines that can be rusted out. You can also pay around $100 or so for a smoke test to find the leak. After that it gets a bit harder trying to pinpoint possible failed components.

 

Not sure if this is relevant but one time I unplugged an injector wire trying to find what cylinder was misfiring and it set a code for evap leak. Have read too many threads where someone has evap leak code and even after a smoke test and so on they couldn't figure it out. Not sure why unplugging an injector would set an evap code but there may be another reason besides a leak

 

You see your leak detection pump over my the passenger fire wall? The large bore hose that is going to the evap system ( not the one to the filter) disconnect it and plug the pump outlet. Also plug the hard plastic wrap line. Clear the code and take it through its drive cycle. Of your code comes back your pump is bad. Easy fix. If not things get harder.

 

The evap system has a combination of plastic and steel tubes that connect the Leak Detection Pump in the engine housing with the cannister behind the rear axle on the driver's side of the vehicle. The connections between the plastic tubing and the steel tubing are made with rubber tubing. The rubber tubing drys out and cracks over time. One connection is under the driver's seat. Crawl under the jeep to check that connection. The other connection is inside the engine compartment. Locate the plastic tube that runs down the center of the fire wall. There is a connection with a steel tube at the bottom of the fire wall. A bright flash light or work light comes in handy. Good luck.

 

What said "Evap leak"?


You should have a check engine icon light on and a set or pending Diagnostic Trouble Code. Can you get it read again using a quality code reader or scanner?

 

All great suggestions I will look into it. It may be worth noting that prior to switching my engine with a new 4.0l I didn't have this code

 

.

 

Yes of course. I had it read. I don't remember what the code was I will have to get it. I meant to say that lol. Point being the code is for an evap leak. When I get the specific code I'll definitely post it. I'm also concerned with the easy option whereas maybe something wasn't plugged in correctly during the engine swap lol. Not sure.

For what it's worth if I remember the code description was large evap leak

 

Finally was able to get the code read again. I have 6 codes. 1 for each o2 sensor bank. why? i just had all of them changed a month ago so im not sure what would cause this.

1 for cylinder 4 misfire (doesnt sound like its misfiring at all, maybe just a spark plug)

1 for evap. p0455.

 

Erase the current codes and lets see what comes up in the future.

 

There are multiple codes for O2 sensors. You can have a code telling you the sensor is bad, or you can have a code telling you the O2 heater isn't working. You need to post exactly which one you have. If it's the latter, you may have a shorted heater circuit. Or you may have just blown the fuse(s).

Right now mine has a brand new O2 sensor in it but keeps blowing the &*%$# fuse and lighting up the CEL, and I haven't had time to figure out where the short is.