ewilliams1990

Hey guys, my girlfriends 1999 honda civic ex just threw some codes.
I went to autozone and had the guy print them out for me.
Its a 1999 honda civic coupe ex with stock d16y8. 134k miles. stock everything. Automatic.

The codes are
P0430. Which relates to air leak of some sort I think.
P0740 and P0700. which both relate to tranny I believe.

I put the car up and inspected the transmission. I saw that the solenoids and connector to some sensor are pretty wet with oil or TF.

I also saw some oil where my tranny meets the engine. Didn't look like a lot at all but I still took a picture to show you guys.







Thanks for the help guys.

Chriser0

Jump the service conecter and pull the D4 codes and all the check engine codes again P0430 is not listed for these cars here. This shows how to pull d4 codes and MIL codes https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/how-pull-cel-d4-srs-abs-codes-code-lists-1901557/

ewilliams1990

I will do that first thing tomorrow, thanks.

EJ8mike

Ok well i had oil on bottom of tranny in same exact place, its probably the rear main seal. I have same exact car. Mine started to leak at 100k mi. Could possibly be distributor o-ring leaking all the way down, but would need more pics up there to verify. I used some AT 205, its just a seal conditioner, totally harmless.....bone dry now!

ewilliams1990

Great tip thanks! And everything up top is dry dry dry; for now at least. I think its the seal, but its not leaking a lot, doesn't even drip from it. I know my oil pan is a little bit leaky and i will get to that, idk if oil can travel that far though haha. Heading to the junkyard tomorrow hopefully will pick up new solenoids if they look decent. We just got her this car, it rides like a dream just the CEL pisses me off. I tend to like everything perfect. Anyways, thanks again.

ewilliams1990

PS is it a bad idea to do a full tranny fluid flush? I heard its not such a great idea to do on automatic transmissions. Thanks

EJ8mike

Noooo

Get 3 qts honda ATF, drain and fill. Easy.

ewilliams1990

CODE 67!
Will a bad cat be throwing off my transmission?
The problem is like this.
When accelerating from 1st gear to 2nd it shifts hard. Thats about all I can say really. And if I accelerate hard, like trying to get up and go quick, it shifts REAL hard. It normally gets to 3.2k~ rpm then shifts.
I replaced two solenoids hoping that would fix the tranny issue.
Any information or help would be greatly appreciated.
Thanks!

ewilliams1990

Okay so my girlfriends car has been having transmission issues. Firstly, she drives a 1999 honda civic ex coupe auto trans and stock d16y8. It has been having problems shifting and seems like a loss of power. Not too sure on the loss of power though. Anyhow, the shift from first to second seems really fast and not smooth at all. It's kinda jumps into second. It has a CEL for 67, which is Catalyst System Efficiency Below Threshold. So today I lifted the car up and removed the connection to cat converter to see if it being clogged was the issue. So I drove down the block going from 1st to 2nd only and it kept shifting badly so I ruled that out. I parked it again and lifted it and reconnected everything then I decided to try the o2 sensor. I disconnected the first o2 sensor before the CAT and went for a ride. The shifting is much smoother and seems like the problem is resolved. So when I get the chance I'm probably gonna pick up a new o2 sensor for it. Is this possible? The o2 sensor throwing off shifting? My old 98 hatchback had a bad o2 sensor which was causing terrible fuel economy and had a bad jump on re-acceleration, once replaced the problem was resolved. Any help would be greatly appreciated guys! Thanks a lot!

ewilliams1990

anyone have any input?

ewilliams1990

Okay, I have posted on this before and recently have done some replacing in order to fix this problem but have hit dead ends. My girlfriends 1999 honda civic ex with stock d16y8 automatic trans is having what I believe is a transmission issue.

Symptoms -
1. Shifts hard from first to second gear. Not like super hard, but definitely not smooth.
2. When I press the pedal down hard, to increase acceleration, it shifts hard.

Parts replaced -
Shift Solenoid
Linear Solenoid

I've checked the fluid and looks clean and the normal redish color.
I've also check the throttle cable and seems to have the correct amount of play.

I have a replacement lock up solenoid but I dont feel like replacing that will do any good.

I have a opportunity to get a 74k mile d series transmission from a wrecked car for about $160. I just want to make sure I try every possible attempt to fix the problem before I give up and just replace the whole trans.

Any input will be greatly appreciated..Thanks

ewilliams1990

Sorry, forgot to mention.

I'm also throwing a code 67.
I currently have the o2 sensor before the cat unplugged and also tested the car with the car disconnected in order to see if it was clogged and back pressure causing the hard shifts. But it didn't fix anything. So it's reconnected now and o2 sensor still out.

strategy400

Helm says 1st to 2nd harsh shift is possibly 12, 19, 20, 29. 50, 51, 57, 58

Former User

Why not reconnect the O2 sensor?

Try doing three serial drain-and-refill cycles of the transmission with Honda ATF or a Honda-recommended ATF. Between each cycle, take the car on a short drive where you also slowly move the shifter through all the gears with the engine running.

Then go from there.

purgat0ry

iTrader: (3)

^^^^

Side note, if you do go for the other trans, see if you can't snake the torque converter with it.

Chriser0

The other transmission has to be one from a Y8

ewilliams1990

Hey guys,
I have a d16y8 engine (both head and block) and to what I believe to be a y7 tranny(auto trans). It has a hard shift into second gear and is throwing the typical code for it being so. I broke the knock sensor on the block. I also have a 37820-P2E-A92 ECU. So if I swap the y8 ECU for this y7 ECU all should be well, right? No code for knock sensor because y7's don't have one and the transmission should switch gears smoothly im assuming. Can anyone confirm/deny this? I know that I will lose vtec. I'm also under the impression that I will have to wire the IACV differently. Any input will be appreciated. Thanks HT.

NotARaCist

iTrader: (1)

You'll also need to swap your injectors. The Y8 ECU looks for "normal" 240cc injectors, whereas the Y7 ECU runs weird 170cc injectors. Run 240cc injectors on a Y7 ECU, and you'll run unpleasantly rich. It'll work, sure, but the richness will wash your cylinders in short order, frying the rings. It'll also leave a rather unpleasant amount of black **** all over your rear bumper. Re-doing the IACV is easy - get a Y7 throttle body. The IACV is mounted on the TB for the Y7, rather than on the IM for the Y8.

Regardless, you'll be gimping yourself pretty hard, and you'll notice the difference. Realistically, you'll be better served getting the proper EX transmission and swapping it on there.

ewilliams1990

It's my girlfriends car. I just want her to have a reliable means of transportation. She needs anything but power, if that's what you're referring to regarding gimping myself.
Also, I won't need to splice anything? Just plug and play after getting a y7 throttle body with the IACV attached? Thanks NAR

NotARaCist

iTrader: (1)

You'll have to do some minor rewiring with the IACV. By minor, I mean extremely minor.




Just do the reverse of that.

ewilliams1990

Thanks a lot man!

NotARaCist

iTrader: (1)

No problem Don't forget the injectors! Seriously, washed cylinders are never fun, and fixing them is never cheap.

ewilliams1990

Yeah for sure. I will scout some out at the local pick-n-pull, along with the TB/IACV combo. Tomorrow I will be reassembling everything and hopefully give it it's first start up in about a week. Crossing my fingers for everything to go well and me remember where everything goes. First head gasket job i'm doing, haha.

tony_2018

I thought y8 automatics use the same 3 wire iacv.

Former User

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