Holy DTC code hell!!! 2008 Limited

[alia176]

Well, the new fuel pump from Toyota is installed and things are running well. I still have the pressure gauge connected to the fuel rail and will see how the pump behaves under load.

One thing to keep in mind when you swap fuel pumps is to move over the O ring from the old pump to the new pump. If you don't, then the pump will have volume but not have pressure. Ask me how I know!

It's a shame that the new fuel pump doesn't come with a new O ring so be sure to order it separately. The attached PDF shows the part # for the 2008 T4R V8.

 

[alia176]

**** problem solved *****

Well this saga has finally come to its end. We took her 4Runner out to the movies after the new fuel pump went in and the engine didn't hiccup one bit. :thumb: Probably wasn't a good idea to go on the maiden voyage in the middle of a snow storm to go see The Martian, but we were anxious to check out the performance.

After we came out of the movie, bunch of DTC's popped up. Couple were 420 & 423 (catalyst below threshold), some were dealing with the rear wheel speed sensors and of course the VSC & slip lights were on the dash. I reset the code, restarted the engine and drove home w/o any more issues. I wonder if I messed with the ABS wiring hardness from back there? I don't think I did that but who knows.

 

[alia176]

Another update, her vehicle has been running silky smooth. No issues with the engine but we're getting P420 and P430 so I think both cats may have been damaged by running too lean. We'll deal with that later.

 

[BMWSTOY]

Glad its running, veery good read

I would have bet a plug or coil pack as my LC ran that way during the intermittent time Cyl #2 was going out.

Super glad you finally figured it out. Great Persistance.

 

[BlackWorksInc]

Another update, her vehicle has been running silky smooth. No issues with the engine but we're getting P420 and P430 so I think both cats may have been damaged by running too lean. We'll deal with that later.

Open TIS, connect to the vehicle, go to ECM/Engine Control -> Datalist and then select all four sensors (Bank 1 Sensor 1 & 2, Bank 2 sensor 1 & 2). Once they are highlighted blue, click the little graph icon on the bottom of the scantool window. It should graph the sensors now rev the engine to about 2500rpm for about a min. Both bank's sensor 2 should basically flatline to the bottom while both Bank's sensor 1 should take normally for good cats.

 

[alia176]

Open TIS, connect to the vehicle, go to ECM/Engine Control -> Datalist and then select all four sensors (Bank 1 Sensor 1 & 2, Bank 2 sensor 1 & 2). Once they are highlighted blue, click the little graph icon on the bottom of the scantool window. It should graph the sensors now rev the engine to about 2500rpm for about a min. Both bank's sensor 2 should basically flatline to the bottom while both Bank's sensor 1 should take normally for good cats.

SIGH, I wish I could use the TIS to connect and Dx but if you might recall, I'm unable to connect to her Engine ECM I can connect to all the ECUs on my '03 but not in her '08.

I wonder if I should try a lower version of the TIS software?

 

[alia176]

** update **

Just letting everyone know that the vehicle has been running super smooth and w/o any issues. We do have a CEL light and the two codes pertain to "catalyst below threshold" on both banks.

 

[Sichko]

I have a problem that's developed into something quite similar to the OPs:

Back story: Driving from TN to CO I woke up in Kansas and it was -10. For the first time since I've owned the truck (5k miles) it had a longish crank. Got home and the problem of a long crank on cold starts persisted. At this point it was fine when starting warm. I thought it was a fuel pump problem and in fact the fuel pump was not holding pressure, so I had the fuel pump replaced. The mechanic tested and confirmed that the fuel pump was now holding pressure. I also replaced the spark plugs.

This was in January. Pretty much since then it has had long cranks when warm/hot (5 seconds) but starts right up when cold. Last weekend I drove it a couple hundred miles (only significant driving i've done since Jan). I started to notice some intermittent power issues like the OP had. And I got the codes p0171 and p0174. Then when I got home it had some real trouble starting - failed to start when hot a couple times - and a couple other times it sputtered and died.

I cleaned the MAF and that seemed to help some - hasn't failed to start since then but still is struggling when warm (5 second crank and some light sputtering).

One theory after reading this thread: I got a bad tank of gas on the TN-CO road trip which messed up the fuel filter / pump. I still had some of the bad gas after the pump was installed (though I had refueled at least once before the replacement) and that contaminated the new fuel pump.

What doesn't make sense is the change in symptoms. Also last time I tried the turn key pressurization test it did not decrease the crank time for the warm start - but I haven't tried this in a month or so now. Maybe the fuel lines or injectors? alia176, did you do anything other than the fuel pump? Suggestion are hugely appreciated!

 

[alia176]

Sorry to hear about your issues. I only replaced the fuel pump that came with a new a filter sock.

Let's totally iron out any fuel issues by checking the fuel pressure at the fuel rail using a pressure kit. I think I may have spoken about that on this thread. If the pressure is holding during the warm crank or any crank then we can move to other areas for troubleshooting.

 

[Sichko]

It appears to be a problem with the new fuel pump. It has pressure of 20 psi. The mechanic in CO put in a Delphi pump. I think that it was slightly messed up to begin with and proceeded to get worse. I am in TN so likely going to get completely robbed for the labor.

Going to be careful that an OEM pump goes in this time.

Is there any difference at all between the pumps from Toyota (Fuel Pump Assembly - Toyota (77020-35112)): https://parts.toyotadm.com/oem-part...0cnVubmVyJnk9MjAwNiZ0PXNyNSZlPTQtMGwtdjYtZ2Fz

And the Denso pumps (Denso 950-0226 Fuel Pump Mounting Kit): https://www.amazon.com/Denso-950-02...coding=UTF8&psc=1&refRID=S9NAGTJY3G4S1R8TXJS3

Also if the Denso is the exact same - does anyone know if that kit has all the parts the Toyota kit has / if this is what I want to order?

 

[pjku79]

Did you guys figure out the second problem? I just went out for a quick drive (maybe 3 miles), parked it for 10 min and when I came back, it wouldn't idle and I got both lean codes. I was able to limp it home. It seemed to run decent once I got it out of first gear.

 

[alia176]

It appears to be a problem with the new fuel pump. It has pressure of 20 psi. The mechanic in CO put in a Delphi pump. I think that it was slightly messed up to begin with and proceeded to get worse. I am in TN so likely going to get completely robbed for the labor.

Going to be careful that an OEM pump goes in this time.

Is there any difference at all between the pumps from Toyota (Fuel Pump Assembly - Toyota (77020-35112)): https://parts.toyotadm.com/oem-part...0cnVubmVyJnk9MjAwNiZ0PXNyNSZlPTQtMGwtdjYtZ2Fz

And the Denso pumps (Denso 950-0226 Fuel Pump Mounting Kit): https://www.amazon.com/Denso-950-02...coding=UTF8&psc=1&refRID=S9NAGTJY3G4S1R8TXJS3

Also if the Denso is the exact same - does anyone know if that kit has all the parts the Toyota kit has / if this is what I want to order?

This thread is about my GF's fuel pump issue so she opted to buy a brand new pump from Toyota. However, I found few Denso pump that I'd have bought for myself if this was my vehicle. So, I think a less expensive Denso pump found on the 'net ought to work just fine.

Let us know which way you ended up going.

 

[alia176]

Did you guys figure out the second problem? I just went out for a quick drive (maybe 3 miles), parked it for 10 min and when I came back, it wouldn't idle and I got both lean codes. I was able to limp it home. It seemed to run decent once I got it out of first gear.

This thread is going to grow so please let us know what is the "second" problem you're referring to.

Without knowing your issue, if you suspect a fuel delivery issue in any way then rent a fuel pressure test kit and isolate the issue. Due to the fact that we took a month or so to isolate my GF's fuel pump issue, she ran "lean" quite a few times. This caused the cats to get clogged with dirty exhaust due to lean condition and now she's getting P420 and P430 codes. So, it's in your best interest to not get the lean codes in the interest of saving your cats. Post #96 has the info on how to check the pressure: http://www.toyota-4runner.org/4th-gen-t4rs/202426-holy-dtc-code-hell-2008-limited-7.html#post2203451

 

[AuSeeker]

This thread is going to grow so please let us know what is the "second" problem you're referring to.

Without knowing your issue, if you suspect a fuel delivery issue in any way then rent a fuel pressure test kit and isolate the issue. Due to the fact that we took a month or so to isolate my GF's fuel pump issue, she ran "lean" quite a few times. This caused the cats to get clogged with dirty exhaust due to lean condition and now she's getting P420 and P430 codes. So, it's in your best interest to not get the lean codes in the interest of saving your cats. Post #96 has the info on how to check the pressure: http://www.toyota-4runner.org/4th-gen-t4rs/202426-holy-dtc-code-hell-2008-limited-7.html#post2203451

Have ya'll considered trying to clean the buildup in the Cats in an attempt to save them?

Don't know if it works or not because I have luckily not have had a Cat go bad/get clogged on me so I could try and save one by cleaning it, but there's many additives and or mechanical methods posted out there that says it's possible to save a Cat that is clogged by cleaning it.

I as well as others I'm sure would be interested to know if indeed this is possible!

 

[alia176]

My plan is to clean her cats and see if we can make the codes go away. Just for S&G, my GF went to the emissions place and her tailpipe sniffed and the numbers are way below the standard. In another words, she is not a gross polluter by any stretch.

 

[alia176]

Have ya'll considered trying to clean the buildup in the Cats in an attempt to save them?

Don't know if it works or not because I have luckily not have had a Cat go bad/get clogged on me so I could try and save one by cleaning it, but there's many additives and or mechanical methods posted out there that says it's possible to save a Cat that is clogged by cleaning it.

I as well as others I'm sure would be interested to know if indeed this is possible!

This is totally possible and we're hoping to clean my GF's cat.

 

[gm350reratliff]

The issue probably isn't that the cats are clogged but are probably damaged from the multiple misfires that the lean condition created.

 

[alia176]

The issue probably isn't that the cats are clogged but are probably damaged from the multiple misfires that the lean condition created.

It's rare for the precious metals inside a cat get damaged, they simply get dirty. Most cats can be cleaned with a proper cleaning process that most of us don't really use or never done. I've never done it but I did work in the airline industry where we cleaned the ozone converters in airplanes. Ozone converters are super expensive so it's worth it for the airlines to have them cleaned and re certified. So, it's a similar process for the most part.

 

[AuSeeker]

It's rare for the precious metals inside a cat get damaged, they simply get dirty. Most cats can be cleaned with a proper cleaning process that most of us don't really use or never done. I've never done it but I did work in the airline industry where we cleaned the ozone converters in airplanes. Ozone converters are super expensive so it's worth it for the airlines to have them cleaned and re certified. So, it's a similar process for the most part.

If you succeed in cleaning them and get the codes to remain off, please post the procedure and material you use in cleaning them!

 

[gm350reratliff]

If you succeed in cleaning them and get the codes to remain off, please post the procedure and material you use in cleaning them!

I'd be interested in a write up on this as well. Actually, I've never heard of anyone cleaning the cats but if you figure out a way, let us know. I've seen cats contaminated from leaded fuel but those simply got replaced. I have also seen the ceramic honeycomb inside shatter from misfires. Some collapse into themselves and plug up the exhaust while others blow out which results in a cat inefficient code and possibly a rattle in the exhaust downstream.