Acceleration Issue

[Insanityman358]

First of all, sorry if this is a repeat, which it surely is with all the amazing posts out there.

I've got a 2005 T4R V8 Limited with 155k miles. About a year ago my check engine light came on. Having that checked out I was informed that it was an O2 sensor. No biggie. I haven't had it repaired yet, but plan to as winter is coming.

More recently I've been having issues with acceleration. Regardless of current speed she wont shift down to accelerate with power, even with the pedal to the floor. After disconnecting the battery to reset the computer the problem went away for about 100 miles of driving before returning. I haven't gone to have the codes read again yet.

In my investigating the forum so far I've seen mention of transmission fluid, catalytic converter, air flow sensor, and throttle sensor. I'd really appreciate any direction on the issue before I give in and just take her to the dealer along with a sack of gold coins.

 

[Rodtheviking]

Vehicle speed sensor?

 

[eternalsoil]

Is it throwing any new codes?
Could be the o2 sensor finally going bad. On my car a faulty o2 sensor pretty much shuts down the entire car, goes into a limp mode. Not sure if the 4runner would do that also. Reseting fixing it temporarily sounds like that could be the issue; computer fixes the fuel/air mixture, faulty o2 sensor slowly changes it back.

This is a slightly educated guess BTW.

Sent from my SM-N920T using Tapatalk

 

[Insanityman358]

UPDATE: The codes are P0420, P2445.

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

P2445 OBD-II Trouble Code: Secondary Air Injection System Pump Stuck Off Bank 1

 

[Rodtheviking]

Give the catalytic converter a shake and see if it rattles. It may be clogged.

And secondary air pump problem, just found out about this myself.

http://www.toyota-4runner.org/4th-g...air-injection-pump-failure-v8s-important.html

 

[Stuffman]

UPDATE: The codes are P0420, P2445.

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

P2445 OBD-II Trouble Code: Secondary Air Injection System Pump Stuck Off Bank 1

You are in Limp mode due to 'Secondary Air Injection System Pump'. Just had this happened a few months ago. If you live in a state where you have emission laws you need to replace the 'Secondary Air injection pump' PIA - I have one for you if you need one.

If not then use this, lot less headache:
Toyota 4 7L Air Induction Pump Bypass Kit Exhaust Port Plates No Cutting | eBay

For P2445: you needed to change out the downsteam O2 sensor.

Temporary fix, every morning you need to pull off the negative or positive terminal off the battery for about 15 seconds (some say 30 mins, but not my experience). This will reset the ECM, you will be good for about 1 day until it syncs up again. The plus side you will have full power, no limp mode. The bad, you will lose all your radio and window settings. Search here for 'resetting your windows' instructions.

 

[Insanityman358]

You are in Limp mode due to 'Secondary Air Injection System Pump'. Just had this happened a few months ago. If you live in a state where you have emission laws you need to replace the 'Secondary Air injection pump' PIA - I have one for you if you need one.

If not then use this, lot less headache:
Toyota 4 7L Air Induction Pump Bypass Kit Exhaust Port Plates No Cutting | eBay

For P2445: you needed to change out the downsteam O2 sensor.

Temporary fix, every morning you need to pull off the negative or positive terminal off the battery for about 15 seconds (some say 30 mins, but not my experience). This will reset the ECM, you will be good for about 1 day until it syncs up again. The plus side you will have full power, no limp mode. The bad, you will lose all your radio and window settings. Search here for 'resetting your windows' instructions.

Thanks a ton. This makes sense to me. It is the Cali model, but I live in Utah where they don't care. Is the downsteam o2 sensor difficult to replace myself?

 

[Insanityman358]

Also, do you have a link for an O2 sensor that would work?

 

[Stuffman]

Thanks a ton. This makes sense to me. It is the Cali model, but I live in Utah where they don't care. Is the downsteam o2 sensor difficult to replace myself?

The downstream is very easy...drive around for a while until hot...spray some penetrating oil (i used PB blaster) a few times....wait until cool. Disconnect the wires first before removal. To remove the O2 sensor, make sure you use an O2 sensor socket...no sense in screwing up. I ordered all my stuff online, so much cheaper than the local auto stores. Some say to use the original denso, its your choice, I did not.

Afterwords, disconnect the battery cable to let the ECU re sync.

Good Luck!!

 

[Stuffman]

Also, do you have a link for an O2 sensor that would work?

Here is what I bought - did not use the (2) Air fuel ratio sensor yet.
4pcs Air Fuel Ratio Oxygen O2 Sensor 1 2 for 2005 2009 Toyota 4Runner 4 7L | eBay


If you want Denso, you need to look them up. I do not know which one to use.

this uses 1/2 inch ratchet
1/2" Dr O2 Oxygen Sensor Offset Socket Vacuum Switch Flare Nut Wrench 22mm 7/8"

 

[toyo]

Remember to perform the re-learning of the body ECU components after you have reconnected the battery.

 

[Insanityman358]

My ebay account wanst working for some reason soI ordered the pump bypass here: AIP Air Induction Pump Bypass Kit & Exhaust Port Plates - NO CUTTING ? Rutech Solutions

I also ordered a new downstream O2 sensor here:
https://www.rockauto.com/en/moreinfo.php?pk=1607108&cc=1430997&jsn=1

 

[Stuffman]

Looks good. Good Luck!

 

[Insanityman358]

Looks good. Good Luck!

I got the bypass part for the Secondary Air Intake Pump & installed. No more limp mode! Super easy too.

I also got a new Denso O2 sensor and a can of Kroil, but I cant get the old one out. It's really nice and stuck in there. Also, I'm not sure exactly which side to replace. Any suggestions?

Thanks for your help.

 

[Wlater Sobchak]

Fault Code P2445: 2015 4Runner

I have a 2015 4Runner that I purchased brand new. It has ~50k miles. My ‘TRAC OFF’ and ‘CHECK ENGINE’ dash lights came on recently. I thought the fuel cap might not be secured so I tightened it, and disconnected the battery. The dash lights went away, but periodically come back. The vehicle is unable to exceed 45mph when the dash lights come on, but works perfectly for a while after the battery is disconnected. I took it to a mechanic today who was unable to recreate the issue. Fault code P2445 came on when he hooked up his diagnostic tool. I’ve seen online that this means its likely related to the secondary air injection system pump. Problem is, I work in Germany for the US military, and parts are hard to come by along with mechanics that know Toyota products well. It’s been two days and my vehicle is running fine even though this fault code hasnt been cleared. Anyone know any work arounds or easy do it yourself fixes for this situation, or does this require a replacement of the secondary air injection system pump?