cats or o2 sensor? any advice would be great

[chazcheetah22]

Hey guys bought an my 2001 4.0 XLT explorer a few months ago and have had nothing but problems due to poor maitinance from past owners need some advice..

Keep hearing that sound like sand in my exhaust and from reading tons of threads on here I came to the conclusion that one of the cats is done for but my check engine light just recently starting turning off randomly for days at a time and coming back on and when it's off my truck runs fantastic and no bad sounds from exhaust but when it's on it chugs while accelerating (misfires I'm guessing) and shakes like it wants to stall out at idle. So now I'm thinking it's o2 sensors since it runs great when the check engine lights turn off..

Please help me out if you can.. I can't afford new exhaust just to have it not be the problem at least not right now

 

[ranger7ltr]

Get the codes checked...

And see what the ECU is telling you...Find an auto parts store or a friend with a code scanner to read them and go from there...

Guessing and throwing parts at a problem is the expensive way to fix it if it fixes the problem...

 

[chazcheetah22]

Damn I forgot to add that I have been there to check I can't remember exact code anymore it's been a few months now P something.. It's been since the beginning of January and it just recently started changing. So I'm a bit forgetful on the details now. When I get home from work I'll sit down and dig into everything I can so you guys can really advise what you think..

 

[J_C]

I'm doubting it's the exhaust. If it were clogged then it would always run bad. If 02 sensor is bad or cat ineffective, you'd get the light but not necessarily running rough/misfiring.

As ranger7ltr already mentioned you need to get the trouble code(s). Offhand I'd wonder if you just need new spark plugs and/or wires. Have they ever been changed? If not, that may be something it's due for anyway then if it fixes the problem... but again, get the codes and go from there.

 

[chazcheetah22]

Okay I'm home now with more time and have everything in front of me.. So the guy I bought the truck from said he just bought it recently for his daughter but she drove it twice didn't like it (RICH PEOPLE.HUUUGE HOUSE) so it probably sat roughly 3 months (winter) driven 3 times. when I bought the truck it ran fantastic for 3 days 3rd day the CEL came on but we didn't get a chance to go in that day. Next morning it won't start at all just turns and turns trying to start but nothing no one I knew could figure out what it was so $1000 later I replaced the battery, fuel pump, fuel filter, IAC, camshaft position sensor. Lastly spark plugs cuz we tested it and it had spark but in the end we were stumped so I threw em in just to try still no start.. Starting fluid in throttle body got it started but it died unless the airbox was connected instantly after the start.. And that's when this all started.. Carbon smell, loud gravel sound in exhaust, rough idle, chugging during acceleration, also my headlights dim everytime it shakes at idle, sometimes acts like itbdoesnt wanna start but always does Carbon smell is gone ran cataclean through twice (CEL would flicker during runs) nothing has been done to it since then.. Found the code from the shop they say it's P0300.. Will bring it in later today for another test.. And no I never did the plug wires I ran out of funds after doing the plugs and then it started. Sorry for the length guys I just don't wanna be asking for help without giving you everything I can.

 

[JusTheUsual]

Okay I'm home now with more time and have everything in front of me.. So the guy I bought the truck from said he just bought it recently for his daughter but she drove it twice didn't like it (RICH PEOPLE.HUUUGE HOUSE) so it probably sat roughly 3 months (winter) driven 3 times. when I bought the truck it ran fantastic for 3 days 3rd day the CEL came on but we didn't get a chance to go in that day. Next morning it won't start at all just turns and turns trying to start but nothing no one I knew could figure out what it was so $1000 later I replaced the battery, fuel pump, fuel filter, IAC, camshaft position sensor. Lastly spark plugs cuz we tested it and it had spark but in the end we were stumped so I threw em in just to try still no start.. Starting fluid in throttle body got it started but it died unless the airbox was connected instantly after the start.. And that's when this all started.. Carbon smell, loud gravel sound in exhaust, rough idle, chugging during acceleration, also my headlights dim everytime it shakes at idle, sometimes acts like itbdoesnt wanna start but always does Carbon smell is gone ran cataclean through twice (CEL would flicker during runs) nothing has been done to it since then.. Found the code from the shop they say it's P0300.. Will bring it in later today for another test.. And no I never did the plug wires I ran out of funds after doing the plugs and then it started. Sorry for the length guys I just don't wanna be asking for help without giving you everything I can.

Im just throwing this out there...

300 means running lean. Cel light flickers is about the worst thing that can happen. That's bad when cel flickers. Mine did that and it was a injector but it was 302 cylinder on middle passenger side. Cel light would flicker when going above like 50 when or giving it power above 2k rpms. Cel flickering like misfire, dead cylinder, something with the cylinders not working right

 

[chazcheetah22]

The CEL only flickered when I was running cataclean through to clean my exhaust.. Now it just comes and goes as it pleases.. I'll hop in one day and it will be off and the truck will be tip top no ****ty sounds or anything then a few days later it will come back on and the exhaust start sounding choked and like gravel in it and all the issues come back with it.. It always has a slight rough idle though. Read its common for this truck but it gets significantly worse when the CEL is on..

 

[swshawaii]

P0300 Random/Multiple Cylinder Misfire Detected

OBD-II Diagnostic Trouble Codes (DTCs)
http://www.explorerforum.com/forums/showpost.php?p=2054355&postcount=2