Last post on May 13, 2013 at 12:52 PM
You are in the Toyota Sienna
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Toyota Sienna, Van
#110 of 126 cannot increase engine speed + check engine light vsc trac off
Aug 23, 2011 (5:46 am)
I seemed to have a battery problem today, was able to get a boost and get started. However, I was unable to accelerate beyond 2000 rpm. The "check engine", "vsc", "trac off" lights came on. I tested the battery, replaced it, lights are still on, still no acceleration. Cannot drive over 25mph. This is a 2006 Sienna.
#111 of 126 2004 Toyota Sienna ck engine light code P0430
Oct 28, 2011 (5:10 pm)
I have a 2004 Toyota Sienna Van with about 140,000 miles on it. My check engine light came on for about a week before I got it checked at a local repair shop while getting an oil change. Van was driving just fine. They pulled a code P0430 - catalyst system efficiency below threshold (bank 2). They had to order the part, so I have continued to drive it. Later that same day, the light went off. The mechanic says he did not reset the computer.
My question is - when you get this code, how definite is it that the catalytic convertor is bad? How long can I wait to replace it? Fortunately, I went immediately to get an emission test done and the van passed. So I can get my tags with no problems next week. It is suspicious that the light went off on its own. I don't want to spend money on this if it is not necessary. But, I don't want to get stranded with kids in the van. The only thing I can think of that was different, is that I was overdue for an oil change. But, not enough overdue that the "maintence required" light came on.
I would welcome any words of wisdom. Thank You!
#112 of 126 Re: 2004 Toyota Sienna ck engine light code P0430 [mhill777]
Oct 28, 2011 (8:24 pm)
I have a 2005 Sienna and on several trips usually on the freeway or highway to Las Vegas while traveling at higher than usual speeds for a time the check engine light has come on. Later on it went off after a few days of normal driving. I do not believe this has anything to do with the oil change schedule. When i get the oil changed at Walmart every 5,000 miles, I always remind them to zero out the maintenance light whether or not it has come on.
#113 of 126 Re: 2004 Toyota Sienna ck engine light code P0430 [mhill777]
Oct 30, 2011 (5:32 pm)
The maintenance reminder system and the engine light (part of the OBDII system) are totally separate. The reminder system is on time & mileage, On Board Diagnostics is the federally mandated emission controls watchdog that monitors systems to ensure a clean exhaust.
So, on to your code... The code you logged was from a reading by the rear oxygen sensor, located behind the catalytic converter. While the front O2 sensor plays a real feedback role in regulating mixture, the rear sensor is just a tattletale device ratting you out to the EPA as a person of low moral character (just kidding...). It is suggesting that there is a real problem, but in no way impacts driveability, emissions, etc. If it wasn't that many states will not grant inspection stickers if this is a hard code, you could drive on forever with perhaps minimal impact, other than a sooty exhaust.
Now in reality, continuing to drive this way could eventually result in a clogged cat, which could degrade performance. So you do want to know why, and get it fixed.
Why did the light go out? Your system has several 'tiers' of code notation, ranging from "something happened, but it might just be an aberration", all the way up to "DEFCON 5" Armegeddon.
"Something happened" codes can go away in as little as 3 'drive cycles' (basically cold starts with some driving). More severe but fixed items go away after 40 cycles.
Sounds like your rear sensor might have sniffed out a one time burst of rich mixture, and it went away. Time will tell if it will return. Summer/Winter crossovers are common times for this to happen, as gasoline is 'reformulated'. Long drives with one pedal position & constant speed followed by a sudden off ramp (a big change in system status) have been known to trigger it on marginal systems.
Proper diagnosis can be difficult but it is essential. It could be a degrading cat, a dirty or compromised O2 sensor, bad wires or connections, or a computer issue. If you don't know what is broken, fixing it can be very costly!
And that concludes tonight's lesson!
#114 of 126 Re: cannot increase engine speed + check engine light vsc trac off [ouch2]
Dec 10, 2011 (9:06 am)
Hi, I'm habving the exact same problem with my 2011 sienna. Did you find out what was wrong and how to fix it? I called the dealer and they weren't much help at all. The mechanic i talked to never heard of this happening before. aahhhrrgg. take care.
#115 of 126 Re: cannot increase engine speed + check engine light vsc trac off [ouch2]
Oct 09, 2012 (8:32 am)
you seem to have the same i had recently ( i have the same car you have). i brought to toyota services and all theyb did is charged me a stupid over $400 and only changed a fuse on ETC( electrical throttle control ) and some others sunnessesary . do not make mistake like me.
#116 of 126 code p0430 was cleared and came on after changing cat bank 2
Oct 09, 2012 (8:31 am)
i have toyota sienna 2006 with code p0430 ,i cleared it,repplaced it and came back on again after driving about 200 miles. I cleared it again it go on again after about 20 miles , i cleared i again and again. At one time the check engine light went off by itself without cleared . Any suggestion ,thank you very much.
#117 of 126 Re: code p0430 was cleared and came on after changing cat bank 2 [joedinh]
Oct 09, 2012 (7:10 pm)
To clarify, you changed the front catalytic converter? Did you also change the lower oxygen sensor?
#118 of 126 Re: VSC & Engine Light Problems - fixed! [robkampen]
Nov 14, 2012 (11:02 pm)
Hello, Thank you for posting your experience with the 2004 Toyota Sienna ABS and Sensor issue! I know it has been a while... I just ran into this today, got the exact same answer from the toyota service as you got... and was wondering if the solution you have posted lasted, or any issues came back later... thank you for the info you posted! Looks like it could help quite a few people avoid spending major $$$ on an unnecessary repair!
Dec 15, 2012 (7:41 am)
I have a 2009 Sienna and it has happened twice for very brief periods. I will be driving along at highway speeds for extended periods and get an alarm. It is a beeping at about 2x per second accompanied a flashing indicator in the upper right portion of the dash near the maint req light. This was so brief (2-3 sec each occurrence) that I couldn't determine what exactly the light was that was blinking. Has anyone else experienced this and what was the problem/solution?