Failed Catalytic Converter and O2 Sensors, or something else?

[96firephoenix]

Got my reman engine all hooked up and ready to run, and it runs like trash.

Engine is a 4.0 SOHC, 2002 Explorer 4door SUV with 5sp manual.

When I say runs like trash, I mean that you have to mash the gas to get any power under load (Think floored in 3rd gear to hit 55mph), and it gets about 3 mpg. That is not a typo, I used 11 gallons of gas to go 35 miles.

It also leans out and dies at idle once the cats get hot.

Fuel filter is freshly replaced, although I'm willing to admit that it may need it again, just based on how old I know the gasoline was.

Current trouble codes:

• P0316, Misfire in startup (first 1000 revolutions)
  
• P0301, Misfire Cylinder 1
  
• P0303, Misfire Cylinder 3
  
• P0172, System Too Rich Bank 1
• P1130, Lack of Upstream Heated Oxygen Sensor Switch Adaptive Fuel Limit Bank 1
• P1131, Lack of Upstream Heated Oxygen Sensor Switch Sensor Indicates Lean Bank 1
• P1152, Lack of HO2S-21 Switch, Sensor Indicates Lean
  
• P1000, OBD2 System Readiness failure
  
• P1409, EGR Vacuum Regulator Solenoid circuit poor electrical connection

Exhaust is still factory original, at 145K miles. Previous engine was dumping coolant and oil through the exhaust. I know I had a buildup of gas and massive backfire when I was motoring the engine to prime the oil pump. Bad enough that my glasspack muffler is shedding fiberglass.

Could this be anything besides the Oxygen Sensors and catalytic converters? The scan tool's code guide also listed failed fuel injectors as a possible cause for the rich/lean codes, and vacuum leak was a possible cause for the 1409 and the rich/lean codes, but I've already checked that.

Should I just replace everything all at once, or should I target the bank 1 heated O2 sensor first, since that has the most codes? I'm inclined to go this route, simply because it's $20 now vs. $450 now... but if you guys with more experience

 

[Hugh Janus]

Why did you drive it before you finished the install?

 

[96firephoenix]

Why did you drive it before you finished the install?

I didn't... dunno where you got that idea.

Everything was connected and i had a smooth idle before I drove it. The problems started after about 5 minutes of driving.

 

[Hugh Janus]

I didn't... dunno where you got that idea.

Everything was connected and i had a smooth idle before I drove it. The problems started after about 5 minutes of driving.

Well I wonder........

Anyways, a little info might help like make, year and engine......

Your scan tool can monitor the O2sensors to see if they're flatlined.

 

[96firephoenix]

Well I wonder........

Anyways, a little info might help like make, year and engine......

Your scan tool can monitor the O2sensors to see if they're flatlined.

I wonder too...
Also, in case you have signatures turned off: 2002 Explorer XLS, 4.0/5sp manual, 4x4
I can read the live data on the O2s, but what should I look for in particular?

 

[lincolnshibuya]

start first on fixing the misfire on cyl 1 and 3. Could be a wiring issue or bad plugs/coils/injector.

next your bank 1 upstream 02 sensor, that tells the ECM to put more or less gas.

 

[Hugh Janus]

I wonder too...
Also, in case you have signatures turned off: 2002 Explorer XLS, 4.0/5sp manual, 4x4
I can read the live data on the O2s, but what should I look for in particular?

Mobile version turns off signatures......

An O2 sensor should show some voltage output - likely bouncing around a bit.

 

[96firephoenix]

Mobile version turns off signatures......

An O2 sensor should show some voltage output - likely bouncing around a bit.

Useful to know for the future.

I'll take a look at what the O2s are doing.

start first on fixing the misfire on cyl 1 and 3. Could be a wiring issue or bad plugs/coils/injector.
next your bank 1 upstream 02 sensor, that tells the ECM to put more or less gas.

Wiring checks out, that was the first thing I looked at when I got those codes. Plugs and wires are brand new. I'll chuck on the spare coil and see if the problem goes away or not... I hope it's not the injectors, cuz those are a pain to do.

I think I'll just replace all the O2 sensors for good measure. At 145K, I'm not replacing parts early, at least.

 

[lincolnshibuya]

Useful to know for the future.

I'll take a look at what the O2s are doing.

Wiring checks out, that was the first thing I looked at when I got those codes. Plugs and wires are brand new. I'll chuck on the spare coil and see if the problem goes away or not... I hope it's not the injectors, cuz those are a pain to do.

I think I'll just replace all the O2 sensors for good measure. At 145K, I'm not replacing parts early, at least.

you could try swapping the coils too, see if the misfire will follow.

 

[96firephoenix]

you could try swapping the coils too, see if the misfire will follow.

It's a V6 with the coil pack, not the V8 with the Coil-on-plug.

 

[jonboyb]

Different vehicle but similar issues. My old Trailblazer one day out of the blue went from running fine to throwing every code in the book related to O2, MAS, misfires, etc. Not enough power to climb ANY grade. Did a backpressure test on exhaust and was at 5psi at idle (should be like 1.5) and any throttle pegged the backpressure gauge. New cat and car was like new. It was high milage and was due, but there was no real warning prior to shutdown. Maybe have someone do an exhaust backpressure test?

 

[96firephoenix]

An O2 sensor should show some voltage output - likely bouncing around a bit.

One of them shows 0V. Replaced offending sensor and still had poor acceleration and O2 errors.

Different vehicle but similar issues. My old Trailblazer one day out of the blue went from running fine to throwing every code in the book related to O2, MAS, misfires, etc. Not enough power to climb ANY grade. Did a backpressure test on exhaust and was at 5psi at idle (should be like 1.5) and any throttle pegged the backpressure gauge. New cat and car was like new. It was high milage and was due, but there was no real warning prior to shutdown. Maybe have someone do an exhaust backpressure test?

Can't really do a backpressure test, but I'm just going to do the Cat at this point.

 

[Drewmcg]

One of them shows 0V. Replaced offending sensor and still had poor acceleration and O2 errors.

Can't really do a backpressure test, but I'm just going to do the Cat at this point.

Did you replace the cats? Did that resolve your problem?
I've got some similar symptoms after replacing my engine--but not nearly as bad, and the truck runs great under load. But getting DTC's for bank 1 misfires at startup. I have new upstream O2 sensors (Bosch, unfortunately), which my scan tool shows fluctuating and working.

I wonder if a bad catalytic converter can result in a Bank 1 (Cylinders 1, 2, and 3) set of misfires. Doesn't make much sense to me. New wires, plugs, coils, and fuel injectors already . . . .

 

[96firephoenix]

Did you replace the cats? Did that resolve your problem?
I've got some similar symptoms after replacing my engine--but not nearly as bad, and the truck runs great under load. But getting DTC's for bank 1 misfires at startup. I have new upstream O2 sensors (Bosch, unfortunately), which my scan tool shows fluctuating and working.

I wonder if a bad catalytic converter can result in a Bank 1 (Cylinders 1, 2, and 3) set of misfires. Doesn't make much sense to me. New wires, plugs, coils, and fuel injectors already . . . .

I did replace the cats, and O2 sensors (all 4 of them), which seems to have solved my problems.

If you still have power under load, at least your cats aren't clogged. They may be completely catalyzed and not working though.

The Misfire codes never came back after I cleared them the first time. Not sure what was up there, but I also had new plugs and wires all around, and the coil pack was working fine.