I had a radiator hose burst this past weekend, got it replaced, then the car started overheating while the car was running idle (at a stop light) but once I started driving the temp gauge would go back to normal. I found out I was given the wrong clamp for the hose which was causing it to leak, got it replaced and now my check engine light is on.

I took it to the Toyota dealer today and they're telling me its the knock sensor thats gone bad and causing the light to come on. Does that sound right? I thought the knock sensor was nothing more than a microphone to pick up knocking sounds from the engine (which my engine isn't doing).

Any thoughts? I forgot to mention the OBD codes were P0154/P0155.

Tammy

 

I wouldn't trust them if they're giving out P codes on OBD-I.
In either diagnostic's port, bridge E1 and TE1 together. Crank the car and count the number the CEL flashes.


Now yes, the knock sensors can go bad... I just replaced one from running nitro in the car.

 

i also have a 93 es.. go to this site, it'll explain every code. althought , no one can still explain to me the difference between code 21 and code 28...

www.troublecodes.net

 

Code 28 - No. 2 Oxygen sensor signal or heater signal; Diagnosis - Open or shorted circuit in the sub-oxygen sensor circuit; Probable cause - Oxygen sensor, Oxygen signal or heater, Sensor heater circuit.

It's the same problem, but the o2 sensor for the other bank. Change the o2 sensor. You can get them on ebay for $15-$30.
Code 21 is the bank #1 o2 sensor.
Code 27 is the sub-o2 sensor (The post cat one, in CA emessions OBD-I cars)
Code 28 is the bank #2 o2 sensor.
You are very luck in that bank 2 is the front bank. So it' easy to change!

Just be sure when you Ebay a new o2 sensor, that it has the little flange on it that bolts on. Ours don't screw in.




Looks like that.

 

actrually i have a code 21.. so i guess it's a bank 1.. which is the one on the back.. umm.. i took your advice on searching on ebay for O2 sensors.. they're around 70 to 200bucks.... are bank 1 and 2 sensors the same?? cuz i notice the bank 2 sensor has only one wire.. and there are sensors with 1,2 or 4 wires..

here's a pic of a sensor, and the cheapest one i found on rockauto.com... does that work for my code 21 problem?

 

They're one wire. I've seen them on a few places going for less than $30 for a non OEM sensor.
For that cheap, you might want to buy two. The OBD-I ecu's seperately tune both engine banks when it comes to fuel.
If the front sensor is old and running rich, no point in having a slightly funky running engine LoL!

Bosch Universal units go for... Around $30 at most autopart stores.

 

thanks buddy.. and thanks for the emails on my other problem with the coolen..

when it's a cool or cold day , i start my car and start driving.. the car has totally no power when the RPM runs up to 4000.. and around 25-30 mph on the dash.. it just totally loss power and won't go up.. like it dies on me but if i keep the pressure on the gas to keep it going 25 or 30 until the engine worms up. then the speed will pick up to normal.. is that the cause of the O2 sensors or something else i have to worry about??

 

It's scary, the 97-01 & 02+ ES have 3 O2 sensors! Not looking forward to that repair lol.

 

So do the 2/3vz's that are california emessions. Normally they only go one sensor at a time tho. I would never replace a post cat o2 sensor, unless the code for it came up. It's only use is in determining if the cat, and help determine if the EGR are both still working.

You only *have* to replace them one at a time, but if you're having to dig into the rear bank's o2 sensor, you might as well change the front one at the same time. If he ahd the opposite problem, I'd tell him to forget changing the rear o2 sensor.


1993ES300x o2 codes don't come up out of the blue either. if you were running that lean (or rich) on half of the engine; It would also explain the large performance loss.