It sounds to me like your injectors may be stuck open flooding the cylinder and unburned gas is flowing into you cat which then burns it becoming red hot. That's definitely a bad situation. Keep troubleshooting until it is fixed before driving it. CAR FIRE = BAD DAY.

 

If it ends up not being an electrical problem then its mechanical. As rare and unusual as this is a broken intake rocker arm would prevent fuel from entering just one cylinder as well.

 

If that were the case, wouldn't you end up with a misfire code as well?

 

A simple vacuum analysis could help to isolate valve problem (Haynes manual Chapter 2, part B, section 4). As another option, it's very easy to pull that valve cover and take a look. After you pull the valve cover, have a friend turn the engine over by putting a 19mm socket on the crank pulley bolt and then observe what the valve train is doing. If you get bad results from the vacuum analysis, check the compression of all the cylinders. From what I have read so far, I still suspect a frayed wire in the injector wire harness that is intermittently shorting to ground and preventing the injector from getting power.

 

If the fuel injector or lets say the wiring harness is bad, would that cause the vehicle to stall out like it has been? I figured it would still run just shy one cylinder, but i guess not if it's clogging up the cat. Another question i have, can i hollow out my cat? That way there is no chance of this happening again (we do not have emissions testing were i live, just visual)? I realize i would have to unplug the o2 sensor, but would i have to unplug both or just the one (at the cat). Keep in mind fellas this is a "beater" vehicle for me to get back & forth to work, thanks.

 

You can't simply unplug an O2 sensor. Same effect as having a hollow cat or a bad O2 sensor. Having raw fuel run through the engine is going to cause problems in time too. Gas will mix with your oil, and your onto even more problems. Fix it the right way and save yourself lots of trouble later on.

 

Alright gentleman this is what i've got so far, saturday i pulled fuel injector #1 & replaced it w/ #4 cleared codes & rechecked, it was giving me error codes 201, 204, 138. so i'm thinking its a bad injector & wiring harness on #1, so i swithced them back cleared codes again and got no codes???? so i'm thinking it's definetly wiring to #1 but also maybe bad fuel injector??? drove it around today ran fine (about 8 miles), check engine light came on about 7 miles into trip (138), so is this a bad wire to an o2 sensor (how do you know if it's bad wiring on up or down stream) or a bad o2 sensor on top of the fuel injector wiring issue? any advice would help, thanks.

p.s. does anyone know where i can get a harness from on the net, i already checked ebay.

 

I think it's safe to say you have an intermittent short in the #1 injector circuit. Use a multimeter and check each contact to ground while you shake the harness. When you get continuity, you've found your short ... fix that wire. Should save you some green.

Now for the 138 code: Have you recently attempted to ohm out the O2 sensor? If you did, you probably damaged the sensor. You can't check an O2 sensor that way. My next question is, have you altered the catalytic converter? Here's what I found on the 138 code:

Causes


A code P0138 may mean that one or more of the following has happened:

• Faulty O2 Sensor
  
• Short to battery voltage in O2 sensor signal circuit
• High fuel pressure (not as likely)

Possible Solutions


Here are some potential solutions:

• Replace O2 sensor
• Repair short to battery voltage in o2 sensor signal circuit

 

never touched the o2 sensor, I think i'm gonna use the defouler trick for that one. also not to sound dumb but how exactly do you do a continuity test, is the car running, do i disconnect the harness & probe inside the harness or the wire before the harness??? thanks

 

O.K saturday i pulled the o2 sensor & did the "defouler trick" & also hollowed out the cat, drove it (no codes) then the o2 sensor codes pops up again as i'm driving it this morning and the front side is pulling to the left hard. then all of the sudden it pops into nuetral and when i stopped to put it back into gear it just makes a rattling sound as if the gear in the tranny are lose??? WTF! any ideas? prior to this i had no tranny issues (no sliiping or anything), thanks.