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Discussion Starter · #1 ·
So, I just drove off the lift after swapping in a 2zz and 6 spd tranny from an 02 Celica. A couple of issues have popped up in the couple miles that I drove it.

1. CEL came on after a few miles. Could be O2 sensor. I may have the wrong one plugged in.

2. Engine hesitates at 6K. Could this be related to the CEL?

3. Cannot feel the timing change in the higher revs.

4. Cannot get into 5th and 6th gear.

This is my 1st engine swap, and for the most part things went smoothly. I'm really hoping these issues aren't too serious. Can anyone give me any advice or suggestions? It would be greatly appreciated.

-Andrew
 

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Andrew you are I are not going to know until you do one thing.

Get the CEL read the post your findings.
 

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Discussion Starter · #4 ·
Yes it has. My friend installed that, so he may have done something wrong. I also got the reverse blockout, which may be the problem.

I went to autozone and got the codes read.
They are:
PO125-Coolant temp sensor insufficient reading
PO135-O2 Sensor
PO141-O2 Sensor

I intend to check all of my sensors and connections within the next couple of days.
 

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Yes it has. My friend installed that, so he may have done something wrong. I also got the reverse blockout, which may be the problem.

I went to autozone and got the codes read.
They are:
PO125-Coolant temp sensor insufficient reading
PO135-O2 Sensor
PO141-O2 Sensor

I intend to check all of my sensors and connections within the next couple of days.
I would clear the codes and see if they come back again. I had the P0125 when I did my swap and it went away.

It is odd to have both 02 sensor heater circuits malfunction so check the connections once more and remember that car is now in limp mode and probably will not go into lift until the codes are resolved.
 

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Discussion Starter · #8 ·
Yep, Danny, I am from FB.

I fixed the shifter problem last night.

Also cleared the codes, and installed the 1zz's coolant temp sensor.

I extended the wire for the O2 sensor from the passenger side of the engine, but only have that one O2 plugged in the only bung available.(post cat)

I intend to put another O2 sensor in upstream of the cat on Tuesday.

All 3 codes came back after a few minutes of driving. We will see what happens after the pre-cat O2 is installed. If the ECU is getting a bad O2 reading will it not accept the reading from the coolant temp sensor?
 

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Yep, Danny, I am from FB.

I fixed the shifter problem last night.

Also cleared the codes, and installed the 1zz's coolant temp sensor.

I extended the wire for the O2 sensor from the passenger side of the engine, but only have that one O2 plugged in the only bung available.(post cat)

I intend to put another O2 sensor in upstream of the cat on Tuesday.

All 3 codes came back after a few minutes of driving. We will see what happens after the pre-cat O2 is installed. If the ECU is getting a bad O2 reading will it not accept the reading from the coolant temp sensor?
There is nothing wrong with the coolant sensor. The reason why you have the code is because your car will not go into closed loop operation. This is due to the 02 sensors not working as they should and the cars coolant will not heat up as intended because it will be running too rich.

You will need an 02 sensor before the cat for not only for closed loop operation but also for the engine to receive the correct fueling. If it were me I would not drive a freshly swapped car until I addressed the 02 sensor pre- cat.
 

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What does the coolant temperature gauge on the dash read?

My guess is you have an air bubble trapped causing the temp sensor to not fuction correctly.
 

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Discussion Starter · #11 ·
Dev, that's what I was actually hoping. That the coolant sensor code was a result of the O2 not allowing things to run closed loop. Thanks for confirming. I wasn't sure.

Silversprint, the gauge climbs slowly and steadily, but it just seems that the thermostat isn't closing. It stays open while in open loop, correct?
 

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Dev, that's what I was actually hoping. That the coolant sensor code was a result of the O2 not allowing things to run closed loop. Thanks for confirming. I wasn't sure.

Silversprint, the gauge climbs slowly and steadily, but it just seems that the thermostat isn't closing. It stays open while in open loop, correct?
The thermostat doesn't have anything to do with the O2 sensors.

The coolant temperature should climb even if you just keep the car in idle until the coolant is at normal operating temperatures unless there is something wrong with the cooling system.

We will see what happens once you fix the O2 sensor code.
 

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The thermostat doesn't have anything to do with the O2 sensors.

The coolant temperature should climb even if you just keep the car in idle until the coolant is at normal operating temperatures unless there is something wrong with the cooling system.

We will see what happens once you fix the O2 sensor code.

Well actually you are right however the car checks the closed loop operation and throws the code because it is not able to heat up the coolant within a specific time because the car is running rich in open loop for a prolonged time. It will register a code indicating insufficient coolant temps. This code can be a result of a faulty temp sensor, thermostat or cooling system problem however because it is associated with the 02 sensor code it is related primarily to that.
 

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I had similar codes when I first did my swap and my 02 sensor problem wasnt that I had a bad 02 sensor it was because I was using a catless down pipe and it needed a 02 conditioner. Ive seen others have similar issues and the cause of the problem was because they didnt use the 2zz patch harness and messed some wires up trying to repin the ecu.

Did you use the 2zz swap patch harness?

What kind of header and down pipe are you using?
 

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Discussion Starter · #15 ·
I didn't get the plug and play adapter. I did get however the VVL connector kit from MWR.

As for a header, I'm using a custom 4-1 piece that goes into the stock MR-2 exhaust. I eliminated the MR-2's 2-1 piece to make it easier to fit.

Stupidly, I only used the one existing bung for an O2 sensor which is post cat, so I'll be installing a pre cat one today. Given that the correct pins still remain on the ecu, this should solve the problem, no?
 

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I didn't get the plug and play adapter. I did get however the VVL connector kit from MWR.

As for a header, I'm using a custom 4-1 piece that goes into the stock MR-2 exhaust. I eliminated the MR-2's 2-1 piece to make it easier to fit.

Stupidly, I only used the one existing bung for an O2 sensor which is post cat, so I'll be installing a pre cat one today. Given that the correct pins still remain on the ecu, this should solve the problem, no?


Did you swap the TPS wires ?
 

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Yes I did. Can you tell me which O2 sensor I should use for pre-cat and post?

Any standard 02 sensor made for 0DB2 will do and I would keep them the same brand.

I highly recommend using the Denso universal 02 sensor and grafting it into the existing harness.

I would also add the bung pre- cat above the 3 and 9 o'clock position.
 

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I meant which O2 wires on the harness of the 3 from the 1zz harness. Sorry, I should have been more specific.
I would use reuse the stock post cat 02 sensor where it was originally because the 02 sensor has a larger bolt face.

Out of the two that originally went into the 1ZZ header I would choose the one with the longer harness so that it can reach the passenger side plug that it must go into. This is the pre-cat sensor.
You will not need the other 02 sensor so keep it aside or sell it off if it has low millage on it.
 
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