code 42

Joined
Mar 1, 2006
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104
Location
Monument, CO
i was checking for codes the other day and i pulled a code 42. the FSM says it a vehicle sensor. there is no page for troubleshooting. should i be concerned or looking for something? on a side not i'm slowly checking everything due to the lack of power while going up hill. i'm currently in lower alabama and the hills here are jokes ( i'm originally for up north ). on a staight away theres all sorts of power and get-up. going up and little ass hill in third gear at 35 to 40 mph is pissing me off. i'm starting to think its a gearing thing, A440, 33's with 4.11's on a OME heavy plus f/r. any way the code 42 thing, what do you guys think?
 
Joined
Dec 11, 2008
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Whidbey Island, WA
I didn't have a code 42 but my 62 was a pig on hills. The 33's are putting a big hurt on your tranny, it thinks you are going uphill all the time. I swapped my gears to 4.88's and away went the problems of no power and a speedo that was way off.

Highway rpm is around 2200 at 60+ and the speedo and odometer now work correctly. Changing to 4.88's will put you back to stock specs. The gear change equals (almost exactly) the change in tire size.

Tony
 
Joined
Mar 1, 2006
Messages
104
Location
Monument, CO
Kynot62, thanks for the gearing recommendation, i've been debating between 4.56 and 4.88 for some time. after further review and alot of reading, i think the cats are partially blocked. i'm going to pull them this weekend and see what happens.

as for the code 42, should i be worried about the ESU possibly beening bad. i have the FSM, what i don't know (and i might just be retarded), what does it meen. theres no page # to reference troubleshooting. i might be just overly concerned.
 
Joined
Mar 1, 2006
Messages
104
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Monument, CO
rockdoc, thanks for the post. i did a lot of reading and do believe i might have a VSS problem. that is probably only part of the issue. my truck does run rich, so i might have bad O2 sensors and i believe that both of my cats have a partial blockage. i'll dig into this weekend and report my findings. thanks for the help.
 
Joined
Dec 11, 2008
Messages
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Whidbey Island, WA
Its nice that the FSM doesn't tell you where to look! But I think Rockdoc is right about it being tied to the speedo. I did find a reference to the Vehicle Speed Signal on page AT-3 in the part about the Governor Valve. Have you noticed any thing strange about the shifting? It could be indicating a tranny problem. Did that thread from rockdoc shed any light?

I would try to find the VSS and check that thing first, the ECU is expensive. Have you tried re-setting the code memory? Pull the EFI fuse for 30 seconds then drive it and see if it reappears. For some reason I get an intermitent EGR code on mine but I can't find anything wrong

I thought my cats were blocked up but clearing them out completely didn't make any difference.

And no you are not retarded or overly concerned, Toyota felt it is important enough for it's own trouble code so it is worth looking into further. After a little searching I did find a speed sensor in the wiring diagram 1-4 and it just may be in the combination meter. After a little more searching look on Page BE-26 and you will find a test for the speed sensor, it's on the back of the speedo. Let me know if this locates the problem.

More about the gears, you may find that 4.56's are not enough of a change with the auto that we have. I don't notice the 4.88's winding up at all and I am glad that I went with them and not the 4.56's. I would try and find someone near you that has made the change and see how their rig runs with the new gears. I would say to come up my way but you are a long way away! I only recommend this because I know it's an expensive change to make if you can't do it yourself (I did my own). If you need more info go to the gear makers websites and start reading up on tire size, engine rpm etc. One final note, the overdrive in our trannys is what makes the 4.88's practical with 33's, drop it into 3rd and the rpms shoot up to 3000 at 60 mph.

Best of Luck

Tony
 
Joined
Mar 1, 2006
Messages
104
Location
Monument, CO
kynot62, thanks for the gearing info. thats next on my list.

as for my findings, MAF sensor, TPS, plugs and wires all check out ok. the exhaust back press is weak coming out the pipe. i was unable to check if the O2 sensors were working ok and i don't have a light for the timing. i'm going to get a laser temp shooter deals and check the exhaust temp in front of and behind the cats. i didn't have the opportunity to check the VSS. i'll post more this week
 
Joined
Mar 1, 2006
Messages
104
Location
Monument, CO
the latest. i followed the FSM's check of the VSS and no dice. i could not get any readings at the ECU connector. the next step is to pull the speedometer and check the connection. how long does it take to pull a speedo? i also checked the O2 sensors and nothing. i did not get a reading with my multimeter. does any one know of another way to check the O2 sensor for operation?
i shot the exhaust with a laser temp shooter deal, ok the outboard cat was reading 178 degrees F in front of the cat and 128 deg F behind it. the inboard cat read 313 deg F infront of the cat and 231 deg F behind it. i do believe i have partial blockage in both cats. however, the difference in temp is worrying me. why the big difference in temp? please help
 
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