1984paul23

my 1999 es300 is still reading bad air/fuel sensors. bank 1 sensor 1 and bank 2 sensor 1. i just got new denso sensors and my light has came back on with in 7 miles. what can i do to try and fix this. the car runs great but cant get rid of this check engine and trac off light

1984paul23

checked for vaccum leaks and cant find nothing. just got the car a month ago. has 116,000 on it

Hayk

iTrader: (1)

What was the part number for the two sensors? And what codes did you get?

1984paul23

1155 and 1133. 234-9009 i guess thats the part number. replaced front and rear with denso. car seems to run great. the check engine light and trac off light have got to go. gas is killing me. i look at the engine every night wishing i can just find a simple air leak or something. i cleaned the mass air flow. only put 93 gas in it.

1984paul23

i replaced front by the radiator and rear by the fire wall. ive been tryn to get rid of this light for 5weeks now. came on the same day i bought it. im sure the seller just unhooked the battery rite before i got there. he says he has no idea and that never happened to him.

msekanha

Have you determined if your car is a California or Federal Emissions?

There are two different sensors for the two..

I believe you need 234-9007 sensors for Cali Emissions. I could be wrong, someone please correct me if I am.

1984paul23

it is california. the sensors are air/fuel denso

1984paul23

so my part is wrong? part number is 234-9009. i didnt have to do no mods to sensors. they both pluged write in. i checked the plugs and they are good. light just wont go away. any help would be great. thank you.

1984paul23

theres a denso on the firewall and in the front is a bosch. on the boxes they both said air/fuel sensors

1984paul23

the two papers that auto gave me read two diff codes. first one is air/fuel ratio sensor circuit response malfunction bank 1 sensor 1. the second code is air/fuel ratio sensor heater circuit malfunction bank 2 sensor 1. any help would be great. thanks so much

DGIKULJOT

Could be your ecu or somewhere the wire is broken. In some cases reseating the ecu connector at the ecu helps since. Since both sensors are throwing codes good chance the ground or power wire is broken somewhere.

Hayk

iTrader: (1)

If your car really is CA emissions and you're 100% sure about that (sticker on the hood, checked the VIN with a dealer), then yes you have the correct part number. I used that sensor to fix a trouble code on my car. The issue I had is that somebody used the wrong oxygen sensor, which was not compatible with CA emissions. If all checks out, I would try resetting the light and seeing if it comes back. Not sure what else could be wrong.

1984paul23

i reset it all the time wishing it dont come back and alway does. i pulled the downstream o2 sensor out just to look at it and it looks the same as my two upstream air fuel sensors is that rite? or should the o2 down stream look diff?

msekanha

Pull both of the sensors out and switch them around and see what happens.

I know for A fact that for both of the A\f ratio sensors used are part numbers 234-9007 and 234-9009. Although they're the same sensors, one corresponds to the short wire and the other the long wire. Forgot which one is which.

I think the best approach is to get rid of the bosCh sensor. Its up to you but I would buy 234-9007 sensor just to keep exact match to your vehicle.

1984paul23

when you say unhook the plug to the ecu do i need to unhook the battery first? someone told me to replace the two gaskets on the intake ** lower and upper} does that sound like a possibilty?