1993 lexus sc300 mpg ?! Awful help !
#17
Driver
Thread Starter
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Odo reads 235xxx , and my exhaust does smell like the cars running rich, no check engine light, the 02 sensors I do not know of
I bought this cars couple months ago of a mechanic who needed money for a paint job for his mk3 supra
My car is not turbo'd yet
I bought this cars couple months ago of a mechanic who needed money for a paint job for his mk3 supra
My car is not turbo'd yet
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#18
Driver
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I took out the old air filter and put in a cone intake
It breathes a lot better now
Engine mods : intake, ngk spark plugs
I replaced all the ignition parts during the tune up
It breathes a lot better now
Engine mods : intake, ngk spark plugs
I replaced all the ignition parts during the tune up
#22
Lexus Test Driver
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Since I've returned the car to stock I've noticed or haven't realized our cars aren't the most fuel efficient. I've also noticed on my car that it takes a lot to throw a CEL check engine light but my car is a 94 OBD1. Can the o2 sensor be defective or need replacing but there isn't a CEL code being thrown?
#23
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The code for the o2 sensor rarely comes on with our odb1 cars, odb2 is much more sensitive to bad o2's because the ecu is programmed to look for that. on odb1 its more of a comes on if its completely shorted kind of thing.
You could be driving on lazy o2's for years before the ecu will tell you, but If you just change them out every 60k like the service manual reccomends you will have much better fuel economy (even every 100k will do alot of good). Poeple will try and go 200k+ on the oem sensor and I can never understand that cause I can get a universal 1 wire bosch for odb1 for $17 shipped on amazon, and you need 2 of them to do the job on a sc3 and they are both right on the exhaust manifold, you don't have to worry about any of the ones down stream unless you have one and there is a cel. Most odb1 SC's only have 2 upstream sensors and no downstream sensor. If you are odb2 you may need the 3 or 4 wire universal sensor and those are like $30 a piece, and you should do the upstream ones, and leave the downstream one alone till you get a cel.
You could be driving on lazy o2's for years before the ecu will tell you, but If you just change them out every 60k like the service manual reccomends you will have much better fuel economy (even every 100k will do alot of good). Poeple will try and go 200k+ on the oem sensor and I can never understand that cause I can get a universal 1 wire bosch for odb1 for $17 shipped on amazon, and you need 2 of them to do the job on a sc3 and they are both right on the exhaust manifold, you don't have to worry about any of the ones down stream unless you have one and there is a cel. Most odb1 SC's only have 2 upstream sensors and no downstream sensor. If you are odb2 you may need the 3 or 4 wire universal sensor and those are like $30 a piece, and you should do the upstream ones, and leave the downstream one alone till you get a cel.
Last edited by Ali SC3; 05-22-13 at 07:40 AM.
#25
Lexus Test Driver
iTrader: (2)
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The code for the o2 sensor rarely comes on with our odb1 cars, odb2 is much more sensitive to bad o2's because the ecu is programmed to look for that. on odb1 its more of a comes on if its completely shorted kind of thing.
You could be driving on lazy o2's for years before the ecu will tell you, but If you just change them out every 60k like the service manual reccomends you will have much better fuel economy (even every 100k will do alot of good). Poeple will try and go 200k+ on the oem sensor and I can never understand that cause I can get a universal 1 wire bosch for odb1 for $17 shipped on amazon, and you need 2 of them to do the job on a sc3 and they are both right on the exhaust manifold, you don't have to worry about any of the ones down stream unless you have one and there is a cel. Most odb1 SC's only have 2 upstream sensors and no downstream sensor. If you are odb2 you may need the 3 or 4 wire universal sensor and those are like $30 a piece, and you should do the upstream ones, and leave the downstream one alone till you get a cel.
You could be driving on lazy o2's for years before the ecu will tell you, but If you just change them out every 60k like the service manual reccomends you will have much better fuel economy (even every 100k will do alot of good). Poeple will try and go 200k+ on the oem sensor and I can never understand that cause I can get a universal 1 wire bosch for odb1 for $17 shipped on amazon, and you need 2 of them to do the job on a sc3 and they are both right on the exhaust manifold, you don't have to worry about any of the ones down stream unless you have one and there is a cel. Most odb1 SC's only have 2 upstream sensors and no downstream sensor. If you are odb2 you may need the 3 or 4 wire universal sensor and those are like $30 a piece, and you should do the upstream ones, and leave the downstream one alone till you get a cel.
#26
Lexus Champion
iTrader: (10)
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Im not 100% sure on the part numbers so double check but I think they are right, I have used the screw in 1 wire and using the screw in 4 wire, haven't bought the 2 bolt kind yet because I have a downpipe with screw in types now.
If you have the odb1 regular 2 bolt type o2 sensor, I think one could use a bosch 12031.
If you have a turbo downpipe or exhaust that uses the screw in types, a 1 wire is a bosch 11027.
There are also denso models similar to both of these, there is alot of choice with 1 wires.
If you need the kind with 4 wires that screws in, I use a Denso 234-4209 and would recommend these they work well.
Not sure on the part number for the 2 bolt 4 wire, but I'm sure you can find it online.
HiPSI, I believe you can use the 4 wire sensor and only hook up the signal wire for the time being (like a 1 wire sensor) so you don't have to rebuy sensors if you are 1 wire and planning on doing the tt ecu mod and going 4 wire. also the aristo ecu only uses 1 o2 sensor, not 2 like the US models. to wire up the 3 other wires to an aristo ecu when doing TT ecu mod, one is power, one is ground, and one goes to heater pin 71B. If you car came with 4 wires, just wire it in.
If you have the odb1 regular 2 bolt type o2 sensor, I think one could use a bosch 12031.
If you have a turbo downpipe or exhaust that uses the screw in types, a 1 wire is a bosch 11027.
There are also denso models similar to both of these, there is alot of choice with 1 wires.
If you need the kind with 4 wires that screws in, I use a Denso 234-4209 and would recommend these they work well.
Not sure on the part number for the 2 bolt 4 wire, but I'm sure you can find it online.
HiPSI, I believe you can use the 4 wire sensor and only hook up the signal wire for the time being (like a 1 wire sensor) so you don't have to rebuy sensors if you are 1 wire and planning on doing the tt ecu mod and going 4 wire. also the aristo ecu only uses 1 o2 sensor, not 2 like the US models. to wire up the 3 other wires to an aristo ecu when doing TT ecu mod, one is power, one is ground, and one goes to heater pin 71B. If you car came with 4 wires, just wire it in.
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