help , help multiple illness!

[oldmanfu]

hey guys, going away from mr2 for a 4 yrs, finally comes back and pick up this project 91turbo mr2 in mn.
she's a project. i want to bring her back to life. here is the trouble.

1. no boost-drive like na, see gage move at 4k to 5k range , maybe 4psi
2. found 2 engine codes- 21 O2 sensor and 52-knock
my question is because of 52 which cause timing to retard, could this throw in the oxygen senor nutts. a phamton 21 code or is it a dead o2 sensor.
3. speedometer not working, loosing nuts at the connection to tranny but can't pull out the cable to test.
anyhelp to bring this 2 back to life is appreciated. oh yes, anybody where i can get a good deal on knock and o2 sensor?

[Zz_005_zZ]

I am not going to be much help here.... but are u a mechanic??
02 sensors don't cost too much money, and I really don't know anything about knock sensors. But I figured at least I would reply so u knew people might actually look at your post, and care about your concerns.... sorry I couldn't be more help: Brian

[JekylandHyde]

If you have code 52, your knock sensor is blown.
The cost just over $100 and are super-easy to replace.

If you are seeing code 52, your timing is going to be retarded preventing full boost.
You are also going to be running very, very rich ... which could eventually affect your O2 sensor (which also costs over $100).

I would buy a knock sesnor and install it.
Then I would reset your codes and drive the car for a while and check codes again.
If you still have the O2 sensor code, clear codes again and give it another week or two.
It's possible that with operating the car under "cleaner" conditions (not a blown knock sensor) you will clean off the O2 sensor. If you can't shake the O2 code, you will probably have to replace that sesnor ... again, that is an easy fix.

[oldmanfu]

thanks guy, i have order a knock from toyota. will keep u guys posted if this 2 can come back to life in the twin cities.

[Zz_005_zZ]

as usual.... the answers are on here again.... I hope I never have to ask for help, but if I do I know where to come to!!

[oldmanfu]

hey guy, finally got the knock sensor installed, but still no boost. code 52 is gone from cel, but code 21 is still lock on. i don't think o2 sensor has a high enough priority for ecu to retard tb from boosting. i am going to take turbo housing apart for inspection. also notice high idle-possibly cleaning throttle body, may ic. i also notice quiet a bit of oil leaking looks like from valve cover gasket. will torque it down. also, i forgot that if ac is on, idle stay at 1800-2000rpm, no drop. any help is appreciated. saw boost gauge move to half at 4k to 5k rpm range today.. i think possible bad ct26, it smoke blue for 1 minute on start up.

[tHa kNiGHt FaLL]

o2 will not not cause your timing to retard.
o2 will cause your engine to run rich.
you can test it w/ a multimeter.
it reads in millivolts and should switch, back forth from high voltage to low voltage.... roughly between 400-1000mv.
if its not switching there is a problem. with the sensor