Clogged catalytic converters causing crank/no start condition?

Hey everybody, longtime reader of these forums, first time posting.
I am the proud owner of a 2004 DC 4.7l V8 SR5 with 304,182 miles. VIN#
5TBDT44164S452419
She was running perfectly until last week…When I got home from work and parked, truck was running great. When I woke up the next morning and started the truck to go to work, I had a rough idle.
I checked for vacuum leaks, replaced air filter, cleaned MAF sensor, cleaned throttle body, cleaned PCV. Oddly, the check engine light was not on, turns out the bulb had blown.
I connected my scan tool and pulled the following codes:
P0300 (random/multiple cylinder misfire)

P0302 (cylinder 2 misfire)

P0304 (cylinder 4 misfire)

P0306 (cylinder 6 misfire)

P0308 (cylinder 8 misfire)

P0031 (o2 sensor low voltage bank 1, sensor 1)

P0051 (o2 sensor low voltage bank 2, sensor 1)

P0057 (o2 sensor low voltage bank 2 sensor 2)

P0134 (o2 sensor no activity bank 1 sensor 1)

Since all the cylinder misfire’s were on the passenger side of the engine, I guessed that the passenger side catalytic converter was clogged. I added a bottle of Cata-Clean on my way to work and the rough idle smoothed out considerably but not completely. I also noticed improved power. That’s where I was at when I park the truck last night. This morning I started the truck and it idled for a few seconds and then stalled suddenly.
Now I have a crank/no start condition(no codes).
I’ve always done all my own work on this truck but this time I feel like I’m in a bit over my head and I’m not sure how to proceed. Any help with this would be greatly appreciated, thanks in advance!

 

Cataclean is a total f'n gimmick and should never be used.
Bad O2 sensors will cause 'P0430' and 'P0420' errors (cat efficiency degraded).
Upstream O2s being bad will also cause misfire.
The fact you've got low voltage on 3 out of 4 O2 sensors is supicious, at least up until I read the CEL bulb was blown, doh.
Misfires on all cylinders down one bank (passenger side) is also very suspicious, as though they may not be getting fuel, or the upstream O2 is fucked on that site.
You don't want to screw around with O2 sensors: Only buy Denso brand, the "exact fit" units, and DO NOT buy on scAmazon or fleaBay
If your O2 sensors were bad for a very long period and you were running rich, your cats may actually be degraded.

 

PS: When you cleaned throttle body.

• What cleaner did you use, specifically?
• Did you spray anything directly into the throttle body?
• Did you take the negative battery cable off for at lesat 10-15 minutes AFTER cleaning to force the ECU to reset?

 

I used CRC Throttle Body + Air Intake Cleaner

I removed the TB from the truck to clean it, I didn’t spray anything into the engine.

I did not disconnect the battery at the time of the TB cleaning (I have since disconnected it but only for a few minutes)

Im heading out now to disconnect it for at least 15 minutes

 

Practical question in the meantime: Do you know if the O2 sensors in the truck have ever been replaced during that 300k miles?

 

I replaced both downstream sensors approximately 50,000 miles ago.

I don’t recall ever replacing the upstream sensors.

 

OEM (Denso) replacements in rear, or no? How many years ago?

Aftermarket parts, even for name brands, you're lucky to get 2-4 real-world years of service life out of them. OEM will usually net you 10+.

 

ignition coil on bank 2? is this a non-vvti?

 

Unfortunately I foolishly went with aftermarket as it was all I could afford at the time(approx 3 years ago).
I won’t be making that mistake again.
My plan is too start by replacing all 4 of the o2 sensors with Denso and see what that does.

 

I don’t know if I have vvt or non-vvt, not very familiar with that area

 

You are non-VVTi, VVTi started in '05 and continued from there on. Don't buy coils yet. This is 90% not coils, at all, period. If it was, switching one from passenger side to driver's side would change the codes you're seeing. But I almost guarantee it's not coils.

Start with the upstream. Specifically the driver's side first, since it's throwing 'no signal' and 'low voltage'. 'Low voltage' is enough to warrant replacement.

Note: You left out an important detail: 4WD or 2WD? The sensors are different (downstream) depending which you have.
Also note: Look up your parts first @ www.densoautoparts.com using the part finder.

​

 

PS - RockAuto is cheaper at $40/ea: https://www.rockauto.com/en/moreinf...u3doVWQNf5lIEr8ZA63au0sGZ/Xou+mEiN65ErteajK2U

And there's a 5% off coupon at www.retailmenot.com

Or SummitRacing is usually free ship, and a couple bucks more and usually free shipping: https://www.summitracing.com/parts/dnp-234-4169

 

Okay, I’ll start with the upstream sensors.

And whoops, its 4WD

 

Wow, thanks for all the info and help and pro-tips!
I really appreciate it!

 

Great stuff as usual @shifty`
I needed a downstream sensor, but question, it says it is recommended to replace up and downstream at the same time. Is that necessary and should I order the little tool for $9?

 

It's in your best interest to order the tool. Tekton makes a nice one.

If you live in a rusty area or it's been a while, it's also in your best interest to carry around a can of Kroil or PB Blaster and quench the O2 sensor threading after a couple of drives where the engine comes up to normal operating temp before trying to break the sensor free, and honestly, even if you don't.

Finally, yes, it's best to replace upstream and downstream at the same time, per bank. Main reason being, old sensor paired up with new sensor may lead to 'false delta' (bad comparison) due to one sensor being old/tired and one fresh/new, resulting in a bullshit P0420/P0430 (cat inefficiency) code.

Whatever you do, DO NOT order your replacement auto parts on scAmazon or fleaBay (sorry, I can't beat that horse to death enough)

 

I’d also recommend to slightly tighten if it’s not loosening to help break the rust bond.

 

Great, and plan to order from RockAuto. Was pricing them on Sparks this morning and the rears were $104 before tax and shipping, so your post saved some coin, thank you!

 

This is a great job to do with the new driver also. Good knuckle-buster of an experience. 1st major job my dad had me do as a kif was replacing a u-joint. That was a blast.

 

Also, check your wiring to the sensors. This could be caused by rodent or other physical damage.

 

Will do, thanks for the suggestion.

 

Hey everybody, I have an update. I replaced both upstream O2 sensors and cleaned the fuel injectors. However, I had a gut feeling that the problem lay deeper(the way the truck turned over was very unusual), so I decided to visually check the timing on my Aisin timing belt(changed 17,000 miles ago). To my surprise and horror and joy, I found a mouse nest, acorns, and a flattened mouse fur pelt jamming up everything. I removed the debris, reset the time, and now she purrs like a kitten
Thank you all so much for your replies, they were all really helpful. You guys are awesome

 

Wow! I'm going to install an actual cat with my cat guard