When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Is the o2 sensor for the stock ecu in the same part of the downpipe?
If you are sourced off the turbo for the waste gate, you can boost above fuel cut when you have in intake manifold leak cause that is usually where the map is tied in.
So going off of that, it could be a leak or you aren't hitting high enough on the tps % and the tps needs adjustment also. you wouldn't be the first to have a leak but its usually the part you welded.
On the other hand if nothing mechanically/wiring is wrong and it was to do with the ecu swap, try resetting the ecu by pulling power and doing a first start when the car is completely cold.
I have had issues when swapping another ecu and the first start is on a warm or hot engine, it seems like it gets confused. I would do a full reset like that and check the vac line to the map is good.
Can you take a video of your next cold start like the last one, I think that would help.
Also did you do anything to the charcoal vapor canister by the firewall. That actually needs to see vacuum every once in a while like from the stock intake setup or be bypassed/open to air so it can relieve tank pressure or vacuum. you might be running lean cause the pump has to fight the vacuum in the tank if you didn't bypass the canister as without vacuum or bypass the tank vent is basically closed till the safety release kicks in every once in a while (on the side of the canister), which you will smell when it happens. I forgot I have had that happen before also with the earlier model SC's. You can't just take the vacuum line off the top of it from the stock intake, you have to have vacuum on that line controlled by the VSV from the intake manifold, or you have to bypass the whole canister from the line coming off the firewall which is not emissions friendly. as a test open your gas cap and see if you hear a large amount of whoooshing or even fuel spray sometimes, some is normal on a hot day but a large amount isn't, if it has a large amount then replace the cap and see if the AFR goes back to normal.
I am not sure what you mean by Vacuum for charcoal canister vented to atmosphere.
The tank vent coming off the firewall needs to be vented to atmosphere, its the larger thick line.
Your idle is way too high on a cold start, you need to back off your idle screw and probably readjust the tps when you are done.
I am not sure why just swapping the ecu out would do all that stuff, it should be as simple as having a working o2 sensor if everything else is right.
So I put all the wiring together and the car wont start.. did the ds62 igniter, vvti coils, jdm non vvti ecu. Feel like I'm getting weak spark also.. would you maybe be willing to facetime me and go over it a little bit to help me ?
So I am not really seeing anything setup wrong then that would explain the symptoms.
Right now it seems you have a higher than normal idle and your wideband is reading lean all the time.
For the higher than normal idle, could be the idle valve is sticking open, throttle blade is cracked open too far, or a leak in the intake.
I think the cracked throttle and the idle being open though would still be seen by the map sensor and your afr's would be fine, so I can't help but think its an intake leak of some kind between the runner and the head.
Maybe the head to intake gasket didn't have a great seal, and after running high boost it leaks now. Or maybe a spot on the welds somewhere.
Did you use a new oem intake manifold gasket for the intake to the head? you can try the slightest bit of carb cleaner in those areas to see if the idle changes.
I am not sure what to tell you other than these ecu's work well when its setup right, but if something is off like a leak etc.. they can take a lot of time to troubleshoot and to get working right which is why I usually say to just use the stock intake manifold.
Also did you block off the egr port? you can't just leave it open if you remove the valve as you will get an exhaust leak from runner #6, which would also let fresh air into the downpipe and throw all the o2's off. usually the egr port on the back of the head is pretty clogged after 20+ years, but I think some 18 psi pulls could dislodge/clear it out pretty easy.
So I put all the wiring together and the car wont start.. did the ds62 igniter, vvti coils, jdm non vvti ecu. Feel like I'm getting weak spark also.. would you maybe be willing to facetime me and go over it a little bit to help me ?
If you put it all together right it should start, so maybe throw some more details in, was there stuff you weren't sure about?
What about map sensor and temp sensor? I don't have time to facetime to go through this mod.
Gonna recheck vacuum lines, change fuel filter and pump. If that doesn’t resolve the lean issue I’m just going to reinstall the oem TB and runners with new gaskets.
Hello.
I have the po456 code on my 2009 GX470 with the check engine, TCS and VSC lights on.
I took it to the local Lexus dealership close to Boston and they estimated the part cost at $1121.35.
No telling how much the labor would end up costing.
Is this actually something that my son(automotive-Tech degrees & VERY skilled) and myself can take care of?
Gonna recheck vacuum lines, change fuel filter and pump. If that doesn’t resolve the lean issue I’m just going to reinstall the oem TB and runners with new gaskets.
Gotcha, running out of ideas so figured I would mention it, make sure that block off plate has a gasket underneath it and has a good seal.
all those exhaust leaks can let in air that the o2 can pickup and then reads false lean.
still sounds more like a leak to me cause of the not hitting boost cut issue.
Originally Posted by BostonGuy
Hello.
I have the po456 code on my 2009 GX470 with the check engine, TCS and VSC lights on.
I took it to the local Lexus dealership close to Boston and they estimated the part cost at $1121.35.
No telling how much the labor would end up costing.
Is this actually something that my son(automotive-Tech degrees & VERY skilled) and myself can take care of?
I appreciate any and all suggestions.
It is realted to the evap system and for a lot of people changing the gas cap helps as it can loose its seal over time.
If that doesn't fix it after a few drives you may have a bigger issue with the evap system.
Your son should be able to look up the code online, there are a bunch of threads on it (most not on this forum) for testing the evap system, this is a hard issue to track down sometimes if it is not the gas cap, could be a leaky hose somewhere, leaky canister, or wiring issue etc..
I’ve been reading through a lot of the NA-T material here on the forums over the last several days. I’ve got an automatic 1995 SC300 and I want to go the JDM GTE ECU route. An A/T GTE Aristo ECU has recently become available near me and I wanted some verification that I’m correctly understanding what I’m reading here on the forums before I make a big purchase.
Sure, what do you need more clarification on?
You will need to do something about your transmission sooner of later. Your automatic is much weaker than a gte automatic, and even though the aristo ecu is automatic you won't have the torque converter lockup on your stock auto for highway driving (it doesn't work its different between the 2), so not as good cruising and it will probably fail sooner.
Everything else is pretty straight forward for 92-95, but auto guys are at a disadvantage you need to have a plan to manual swap or install a gte auto, and believe it or not the wiring is different enough between ge auto and gte auto that installing a manual is much easier and will hold more power for less $ vs building a gte auto.
So you need the ecu plan which you can use the tt ecu mod, you need all the turbo items to bolt on, you need an upgraded fuel pump/injectors, and you need a plan for your transmission.
I am glossing over a whole bunch of little stuff here. my point is that the ecu, map sensor, and coils is just a small portion of what you need to properly go turbo.
Do not plan to use the stock automatic, if that is your answer before investing the thousands of $ to get all the turbo parts and ecu etc.. then just stop right now and leave it stock.
As long as you have a plan for all the bits, then yeah going turbo is a lot of fun, but going halfway is not especially when you blow your transmission.
Hope that helps generally, but if you have more specific thoughts or questions then ask away.
04-27-20, 01:47 PM
