NoLimitzBuilt

Ok I got the header and exhaust, got it put on this weekend. The CEL light came on, I put the one of the Anti Foulers in there and the light is still on. I see that it needs both of them, so I am going to do that tonight. Here is one of the questions. I cant disconnect the battery as I have a 25 farad cap in the back that I cant get to so it keeps voltage there. How many starts does it take to reset it without the battery being disconected or can I unplug the ECU and do the same thing?

Other question is that I have a Air/Fuel guage and it goes nuts now. Is there anyway for it to work like it used to. Will the anti-foulers fix that? Cause the sensor wire is tapped into the wire off the second O2 sensor.

The_Instigator

You can pull the fuse to the ECU from the fuse block for a few minutes and that should clear the CEL...I dont know which fuse though. As far as the AFR gauge, I have no idea...might be a qustion for the electrical section.

NoLimitzBuilt

does anyone know what fuses to pull to wipe power from the ecu, I pulled the one in the car that said ECU and pulled the one from the motor that said ECU and it still didnt clear it.

The_Instigator

FYI, you should leave them out for a little while like at least10 minutes or so. Im not sure how long you left them out.

NoLimitzBuilt

ok, so I went and had the code read and it came as bank 1. he cleared it. so we will see if it comes back now. I thought it was always bank 2 the code was 0420.

aarontrini85

bank one should be at the the one atached to the header i belive........ sounds like you might have messed it up when you intsalled it in to the new header but i dont know


and just to be sure you didnt attach the anti fouler to the header did you??? you did the o2 sensor that is further donw the exhuast correct???

NoLimitzBuilt

The anti fouler is on the second sensor. I didnt touch the first one except taking it out and putting it back in. I had them clear the code so we will see if it comes back on.

NoLimitzBuilt

so I hzd them clear it and it hasnt came back on.. Knock on wood... but I got the anti foulers in there and it seems to be working.

NoLimitzBuilt

so the code came back on. it stays off when I have it cleared until I start the car for the second time. It can run the first time for however I want to drive it, but once I turn it off and then back on the CEL kicks on within a couple minutes. What is this effecting if it is throwing the CEL for the 1st sensor?

ILLCRXSI

bank1 refers to all 02 sensors on this car. to be able to tell which sensor is throwing a code you need to know which number sensor it is. such as bank 1 sensor 1 for the one in the manifold bank 1 sensor 2 for the one in the s pipe.

your guage is going wild now because you don't have a precat anymore. previously having your guage hooked up to the second sensor did absolutely nothing because it was after the cat. now that there is no cat in front of it your guage is going wild because it's actually reading the 02 in the exhaust like it should have been doing before. 02 sensors that adjust a/f constantly vary in voltage from high to low(which is what sensor 1 is for). 02 sensors that monitor the cat stay at the same voltage which is what sensor 2 is for. a a/f guages should never be hooked up after a cat.

but since your guage is going crazy now it means that sensor 2 is varying in voltage telling the ecu that the cat is bad and throwing a code. anti-foulers suck buy one of the electronic ones that send the right voltage to the ecu so that you don't throw codes. and rewire your guage up to sensor 1. a/f guages are pointless too, since the voltages change so fast that the only way you can make any sense out of it is to look at it with an oscilloscope. a light on a guage doesn't cut it.

Jowie

Ok, from what I gather looking at tech docs on techinfo.toyota.com, the first sensor, on the stock manifold, is the A/F sensor, and is upstream from the first TWC. The second sensor is the O2 sensor, and is located after the first TWC, but BEFORE the second. Right?

If this is true, as far as the ECM is concerned, it only "sees" the first TWC. So by installing a header and getting rid of the first TWC, the second sensor, which is the O2 sensor, no longer has a TWC in front of it, thus the need to "fool" the ECM with antifoulers, etc. Well, I wonder, if one were to keep the second TWC, but move that second sensor to a location AFTER the second TWC, would the CEL problems go away? From what I read, the second TWC is there for the following reason: "To comply with the ULEV exhaust emission regulations, an under floor TWC is used." Do the aftermarket exhausts, the ones that are more then just axle back, remove the second TWC? If so, I think id try putting a high flow TWC where the stock second TWC used to be, and move that O2 sensor to a bung welded on after that high flow TWC. Anyone with headers try this?

NoLimitzBuilt

so what exactly does the first sensor do in the exhaust system then? If the second one is reading the measuremants and that is the determining one, then what does the first one do? I am getting the CEL from the first one. so it has to do something in the grand scheme of things.

ILLCRXSI

the first one adjusts a/f ratio the second one monitors the precat. from what i've read in your posts you still don't know which one is throwing the code all you have said so far is bank 1. please read my above post.

it's probably BANK 1 SENSOR 2 that is throwing the code. this is the second 02 sensor. that sensor is for monitoring the cat. you no longer have a cat, the sensor sees this and throws a code. that means it's working right. you need to trick it so that it thinks there is a cat there. that is what an anti-fouler is for. and as i stated above anti foulers suck, it is better to use an electronic device that sends the proper voltage to the ecu to make it think there is a cat. edit: i think zpi makes one of these. it costs more than an anti fouler but it works a hell of a lot better in my opinion.

NoLimitzBuilt

I PMed you.. I did read the post and that is why I PMed you. Ok I used to have a mustang and did the whole X pipe and it through a CEL. The sold some resistors that you cut and put inline on the sensors. I wonder how hard it would be toi figure out the voltage and make the resisitor packs so that it would fix this issue. My mustang one was awesome. easy to put in and never had a single issue. Even went through emmisions missing all the cats and passed. Thank god they didnt look under the car.. LOL.. they just plug in the scanner and check for codes and let you go if it passes.

ILLCRXSI

yeah i got your pm sorry if i sounded angry before. lots of people on here will try to tell you that the 02 sims don't work, but they do. i would spend my money on one of those befor i stacked some anti foulers in my s pipe.

The_Instigator

I think it makes more sense to try the $6 mod to see if it works first before trying the much more expensive mod. I have the anti foulers and have no problems and mileage didnt change from stock.

NoLimitzBuilt

I have a plan that I am going to try. I will let everyone know if it works.