sluggish/rough/slow acceleration (1 Viewer)

[landarcht]

Today I suddenly felt my 2005 100 felt a bit sluggish and what felt like light jolt as I accelerated. Has never happened before. Wondering if this is the CAT P0430 or the P0156 O2 sensors finally catching up? I had the P0430 light for almost two years now, but then a few months ago the code switched to P0156 after my mechanic suggested a spacer but the didn't do it because the flange was too tight/hard to remove and he didn't want to risk snapping the bolts. Again, this behavior just started this afternoon and only happen during initial acceleration and up to about 20-25 mph range then I felt going away.
Any idea?

 

[landarcht]

Condition has slightly worsened, it feels bumpy whenever I accelerate at around 45 mph, not sure if this has to do with CAT perhaps plugged? I'm no longer driving it until I take it to the shop next week. Just wanted to know what potentially could be wrong before hearing from the mechanic.

 

[landarcht]

I got the above two codes when I scanned my rig this morning, already have made appointment with mechanic next week. Wondering if it is safe to drive to him (about 9 miles) or should I have it towed? I drove back from work the other day it was a bit rough on low speeds like a jerking motion. Any idea what may be the issue? Just wanted to know what I may expect. Did some research on what could cause those two codes, likely spark plugs, coil wires and O2 sensors? I used to have P0430, but it went away.

 

[2001LC]

I would check #3 spark plug, before starting again. Make sure it tight! You can then swap coil #3 with #1. Clear codes and see what returns. Or have it towed to shop.

#3-BK1 (Drive side of engine (LHD), left as you sit in seat) second plug from front of engine. It's a very easy plug to get at.

BK2 - 2, 4, 6, 8.
BK1 - 1, 3, 5, 7.

Disclosing year and miles in signture line is helpful. Or list every time you've and issue. 98-99, 00-05 or 06-07 have common issues by year!

 

[landarcht]

Hey 2001LC, I think I have consulted you before with my rig. It is 2005 with about 187K miles. I have had the P0430 code for about two years now, never had any issues, it is my daily driver (with lights on) and no issues whatsoever but this time I think the CAT (bank 1 is OEM, bank 2 is Magnaflow about 6-7 years), may be CAT is finally plugged up? Or time to replace spark plugs and coils (been many years since last done), or fuel pump or something else? Mileage has been consistent about 300 miles out of a full tank. It would be a bit challenging to buy a factory OEM Cat at this time if that is the issue, hoping it is not. Just fared through Ian, the timing is not so great...
Few months ago my mechanic replaced Bank 2 O2 sensors and was trying to use the flange/bong as a spacer to rid of the P0430 code, but he didn't do it because the bolt is too tight and he was afraid it would snap off due to age. But since replacing the O2 sensors, P0430 code went away and P0156 appeared. It wasn't until couple of days ago when the low speed/or during acceleration jerking started to happen, that's when the #3 misfire code came up this morning when I decided to scan it. I feel the jerking action has worsened so I'll have my car towed to the shop instead of driving there. The car still starts on first crank and idles fine until you start driving it, then it will get a bit rough. The rig is in good condition overall so I want to keep it as long as I can.

 

[Trunk Monkey]

if you've been driving on bad o2 sensors for years as you say, you've probably fouled the cats. Don't know why you wouldn't just replace the o2 sensors and not with spacers to try to loophole the issue.

 

[J1000]

Hard to really know what's going on it seems like this truck is overdue for maintenance at the minimum.

Jerky acceleration to me sounds like a fuel problem, either too much or not enough. Combined with O2 codes I'd look into fuel. Clean MAF if it hasn't been in awhile.

Does your truck have the infamous exhaust header tick? If so you may have finally melted out your cats otherwise your are probably well on your way to destroying them. Going from a front O2 sensor code to a rear O2 sensor code definitely sounds like the cat is done.

 

[landarcht]

Just to clarify, O2 sensor code came up in the last 2-3 months after replacing the bank 2. I've been driving with P0430 code for couple of years with no issues whatsoever. Bank 1 is factory OEM Cat, Bank 2 is Magnaflow about 6-7 years old, that's the one throwing code but drives perfect. Soon as the P0156 code came up, the P0430 code was gone, but as of today, it's the P0303 cylinder 3 misfire, first time ever. I posted about that issue earlier today. I'm getting the truck towed to the shop next week. MAF was clean but I cleaned it anyway. Truck always serviced regularly.

 

[J1000]

Just to clarify, O2 sensor code came up in the last 2-3 months after replacing the bank 2. I've been driving with P0430 code for couple of years with no issues whatsoever. Bank 1 is factory OEM Cat, Bank 2 is Magnaflow about 6-7 years old, that's the one throwing code but drives perfect. Soon as the P0156 code came up, the P0430 code was gone, but as of today, it's the P0303 cylinder 3 misfire, first time ever. I posted about that issue earlier today. I'm getting the truck towed to the shop next week. MAF was clean but I cleaned it anyway. Truck always serviced regularly.

Right, running your truck with a screwy air-fuel ratio for 6-7 years is exactly how you melt your cats.

P0430 is Bank 2 cat below efficiency, meaning the ECU thinks the cat is not working correctly. Could be, or it could be another issue causing the cat to not work right.

P0156 is Bank 2 downstream O2 malfunction, either the O2 sensor is bad or there are further issues with the cat and fuel on Bank 2.

Misfire could be from any number of things.

 

[2001LC]

The most import thing to do, before replacing a CAT. Is determine why it went bad, and fix what caused it to go bad. Otherwise you'll keep taking out CAT. Driving with CEL on, or trying to fool the ECU (ECM) with 02 extenders, are things best not done. 200K miles CAT should be good condition. If upstream always as should be.

If you came to me, I'd:
As I had recommend, I would be looking very close at #3 plug, before starting. I fear #3 spark plug has blown out the head, or near doing so. I likely want to do a compression test. As you not only have BK 1 (P0303), but BK 2 (CAT & O2) issues. Which test, gives me look at all spark plugs and coils as I do. If compression good enough. I'd finish tune with new spark plugs. Correct all vacuum leaks. Make sure well turned at all points. Check for exhaust leaks. Check fuel pressure. As I go through inspecting and tuning engine. I should find "things" which could point to why you had a bad CAT and may again.

Once engine as it should be: I'd clear codes and see what if any codes come back. I'd suspect the P0156 will return, and I'd replace BK2S2 02. I also suspect, I find # 3 coil and/or plug issue.

"Truck always serviced regularly" I get so many 100 series, that have many service records. Owners feel it was regular serviced as it should be. But I find many holes in service history and many things done wrong. Even Dealership service is not insurance all as it should be. But them or someone that works only on Land cruiser, is best bet. The worst are the corner INDY shops that work on all makes and models. Midas okay for mufflers, but nothing else. Brake plus, lube center, etc. I'd not step a foot into. But no shop is a substitute for studying and understand, the Toyota maintenance schedule and using mud tech section to fill in it's gaps.

BTW:
Old bad CATs themselves can give clues as to why it went bad. Like impact busting up CAT. Burnt out indicting air fuel issues.
From all accounts in mud, which I've not checked this personally. 98-05 OEM CATS are no longer available.

 

[landarcht]

Got my rig repaired. Replace all spark plugs and engine coil due to misfire. Will be taking to a muffler shop to take care of the CAT and O2 sensor issue. This mechanic does not have welding capabilities. Car is driving normal now.