# Toyota Sienna 2002 intermittent cat efficiency code **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [September 15, 2014, 11:13pm UTC](https://community.cartalk.com/t/toyota-sienna-2002-intermittent-cat-efficiency-code/87199 "2014-09-15T23:13:31Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![irlandes](https://avatars.discourse-cdn.com/v4/letter/i/b5e925/32.png) [@irlandes](https://community.cartalk.com/u/irlandes)\ **Post date:** [September 15, 2014, 11:13pm UTC](https://community.cartalk.com/t/toyota-sienna-2002-intermittent-cat-efficiency-code/87199/1 "2014-09-15T23:13:31Z")
My 2002 Sienna has had the intermittent cat efficiency failure off and on (well, I said intermittent, heh, heh) over the years. In the past, I have posted on this topic, and smart folks here said there was new software which solved this problem in many cases. I asked Toyota in Pharr a couple years ago about flashing it to the new engine computer version. The service writer told me I would need a new computer and it would cost $800, which I believe is considerably more than flashing would cost. I just looked up the Service Bulletins for that car, and found TSB-0064-10 which says as follows: Service Bulletin No.: TSB-0064-10 Component(s): ENGINE AND ENGINE COOLING NHTSA ID Number: 10034284 All Products Associated with this Service Bulletin expand Details close 0 Associated Documents Manufacturer: Toyota Motor Corporation SUMMARY: TOYOTA: TECHSTREAM ECU FLASH REPROGRAMMING PROCEDURE. FLASH REPROGRAMMING ALLOWS THE ECU SOFTWARE TO BE UPDATED WITHOUT REPLACING THE ECU. FLASH CALIBRATION UPDATES FOR SPECIFIC VEHICLE MODELS/ECUS ARE RELEASED AS FIELD-FIX PROCEDURES DESCRIBED IN INDIVIDUAL SERVICE BULLETINS. MODEL YEARS FROM 2001-2011. \*PE Another page said it was implemented in 2010. And, the ‘All products’ on this page said the SB covers Sienna 2001 through 2011. Do I read this correctly? If so, I want to take it in and have it flashed to solve this problem. But, if I am reading it wrong I don’t want to look stupid. ---
**Author:** ![irlandes](https://avatars.discourse-cdn.com/v4/letter/i/b5e925/32.png) [@irlandes](https://community.cartalk.com/u/irlandes)\ **Post date:** [September 15, 2014, 11:19pm UTC](https://community.cartalk.com/t/toyota-sienna-2002-intermittent-cat-efficiency-code/87199/2 "2014-09-15T23:19:46Z")
I found this while following the link on the exploding air bag thread to see if my car was on the recall list. Apparently not. ---
**Author:** ![SteveC76](https://avatars.discourse-cdn.com/v4/letter/s/958977/32.png) [@SteveC76](https://community.cartalk.com/u/SteveC76)\ **Post date:** [September 15, 2014, 11:26pm UTC](https://community.cartalk.com/t/toyota-sienna-2002-intermittent-cat-efficiency-code/87199/3 "2014-09-15T23:26:47Z")
Its not a reflash but a new ecu for that year. tsb eg 047-05 your tsb is obsolete ---
**Author:** ![irlandes](https://avatars.discourse-cdn.com/v4/letter/i/b5e925/32.png) [@irlandes](https://community.cartalk.com/u/irlandes)\ **Post date:** [September 16, 2014, 12:05am UTC](https://community.cartalk.com/t/toyota-sienna-2002-intermittent-cat-efficiency-code/87199/4 "2014-09-16T00:05:41Z")
The confusion for me is your document which says to replace the computer was dated 2005, and the document which says it can be flashed is dated 2010. So, I am confused how a 2005 document can obsolete a 2010 document. However, at least the topic is correct, which was my concern. I guess I will go into Toyota and talk to them when I get back now that I have some confidence that I read it correctly. Since it requires another device to flash it may come down to whether the dealer prefers to sell $800 computers or to flash the existing one which would require the purchase of a techstream programmer. ---
**Author:** ![irlandes](https://avatars.discourse-cdn.com/v4/letter/i/b5e925/32.png) [@irlandes](https://community.cartalk.com/u/irlandes)\ **Post date:** [September 16, 2014, 12:14am UTC](https://community.cartalk.com/t/toyota-sienna-2002-intermittent-cat-efficiency-code/87199/5 "2014-09-16T00:14:49Z")
[http://media.fixed-ops.com/toy\_servicebulletins/sb0064t10.pdf](http://media.fixed-ops.com/toy_servicebulletins/sb0064t10.pdf) is the SB details. Note 2010 date. I am still not clear that this would pick up the spec change for P0420. But, I have seen others talk about flashing the computer to fix that problem. I will be traveling to the Midwest. If McAllen can’t do it, I will ask again in the Midwest. Or, maybe call Toyota offices and see if they can find a dealer who can do it. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [September 16, 2014, 12:31am UTC](https://community.cartalk.com/t/toyota-sienna-2002-intermittent-cat-efficiency-code/87199/6 "2014-09-16T00:31:37Z")
TSB-0064-10 was replaced by T-SB-0012-13 REV1, the revisions just add model years to the bulletin. This bulletin is just a general guide to the software update procedure. There must be software revisions that apply to your PCM for this to be possible. The software revisions will be shown as a link in the specific service bulletins. Each bulletin with a software improvement for you vehicle involves replacing the computer, I don’t see any software flashes. The next time you are at the dealer ask them to do a computer “health check”, ask for the print out. This only takes a few minutes and will show if any software updates apply to the computers in you vehicle. ---
**Author:** ![SteveC76](https://avatars.discourse-cdn.com/v4/letter/s/958977/32.png) [@SteveC76](https://community.cartalk.com/u/SteveC76)\ **Post date:** [September 16, 2014, 7:52am UTC](https://community.cartalk.com/t/toyota-sienna-2002-intermittent-cat-efficiency-code/87199/7 "2014-09-16T07:52:29Z")
The tsb you refer to is a generic reflash procedures. The one I posted is for your specfic concern of P0420. Your year will require the ecm to be replaced.