I followed the wisdom of the board, searched, researched and studied. I swapped out my problematic EJ25 in my 98 Legacy GT for an EJ22 out of a 97 Legacy wagon. Both cars are 5 speeds. Now when running, I get codes telling me both O2 sensor heaters aren't working, the knock sensor is throwing a code, and no EGR.

 

Everything is connected as it should be. No vacuum lines are missing or disconnected.

 

Was there something I missed during the swap?

We need exact codes.

 

This many codes usually means there is a wiring issue. Poor connections, connectors unplugged, pinched wires, that sort of thing.

Check the wires on the O2 sensor plugs, they can often get pulled out by accident and will lead to this sort of trouble.

 

Did you use the knock sensor form your old engine or from the new one?

for an EJ22 out of a 97 Legacy wagon. Both cars are 5 speeds. Now when running, I get codes telling me both O2 sensor heaters aren't working, the knock sensor is throwing a code, and no EGR.

 

Everything is connected as it should be. No vacuum lines are missing or disconnected.

 

Was there something I missed during the swap?

 

double check the front o2 wire connector. open it, check the pins, clean it if needed and re-connect. do the same with the 3? big wire connectors on the passenger side rear of the engine at the trans. check to see if any pins are bent. it sounds like something is disconnected as far as the o2 and knock codes go.

 

but as for the EGR, you will never get rid of that one. you should have used an engine from an auto trans car. those are the only ej22s that have EGR. and ALL 96 - 99 ej25s have egr. i hope a CEL will not stop you from getting your car inspected.

Used the knock sensor that came with the EJ22, I can swap the 2.5 one in though (the connector is fine).

 

Double checked the O2 sensor pins already, but didn't check the 3 big connectors all that closely.

 

I'll do those checks and write down the Code #'s

 

I'm not concerned withthe EGR code, just throwing it in there for reference. That won't put me in limp mode!

O2 sensors can fail immediately following a swap - I've had it happen. Especially if the failure was head gasket related. Check connections first of course.

 

Knock sensor is probably just bad - they crack and moisture seeps inside them, etc. Try the one from your 2.5.

 

EGR could be a blocked passage or you used a 2.2 without an EGR .

 

GD

Did I fail to mention the 2.2 doesn't have EGR:brow:

Ah - yeah you just said you weren't concerned with it. But indeed you will get a code till you come up with a way to give the EGR flow sensor some exhaust gasses.

 

GD

Didn't you post another thread about pulling wires out of your o2 sensor connector and wondering what the pinout is? Are you sure you don't have wire(s) going to the wrong terminals? Alternately, if you powered up the car before you discovered the loose terminals, it's possible something shorted to ground and damaged your o2 heater circuit.

 

Why not check for voltage on the o2 sensor heater wires with a voltmeter? I'm guessing that the o2 heaters are turned on by the ECM/ECU so you may have fried it if the heater wiring was shorted to ground.

 

Good luck,

 

Nathan

Yup, checked that already. Not shorted to ground, just an open circuit. The wires pulled out on the sensor side. The wires got stuffed back into the correct holes with the help of wtdash!

 

Wife and I already agreed the car has been too much trouble for what it worth and is destined to be a trade-in.

Once you have the EJ25 out of there it shouldn't be "too much trouble" anymore. You have got rid of the biggest headache by putting in the more reliable engine. Would be a bit silly to get rid of it now - especially to do a trade-in. Someone will appreciate what you have done and give you a lot more for the car just selling it on craigslist.

 

GD

If you pulled on the wires hard enough to rip them from the connector, perhaps the connection is broken internally where it goes into the o2 sensor as well. Do a resistance/continuity check of the 02 sensor heater.

 

I second General Disorder here- I did an EJ22 swap on a 180K mile '98 Outback 5-speed and have had a solid 5+ years of never-had-to-walk hardly spent a dime motoring since. Only routine wear items (brake pads, struts, ball joints, exhaust) in that time & one rear o2 sensor. Just recently it needed its first real repair- bad MAF sensor, $50 off of E-bay and it's back to running great.

That's normal I think...unless you swap an ECU (TCU?). A couple of electronic values become different so it causes a voltage bias somewhere in the circuitry that makes the ECU generate a code.

 

 

If the shops are really nitpicky about the CEL light being on just disconnect the battery before you show up to reset the 'puter and be sure to wear dark sunglasses (so they can't see your lyin' eyes). :-)

 

 

--Damien

If the shops are really nitpicky about the CEL light being on just disconnect the battery before you show up to reset the 'puter and be sure to wear dark sunglasses (so they can't see your lyin' eyes). :-)

 

That doesn't work - testing stations check the readiness monitors. If they are incomplete they will tell you to drive it around and come back in 50 miles. By then the light will return.

 

GD

Well then take it into an Autozone and have them erase the codes...apparently they offer that service for free...at least they did a few years ago...I don't know...maybe their store policy has changed since then.

 

 

 

--Damien

Well then take it into an Autozone and have them erase the codes...apparently they offer that service for free...at least they did a few years ago...I don't know...maybe their store policy has changed since then.

 

You don't seem to understand here - erasing the codes (by ANY means including resetting the ECU, clearing the code via OBD-II, or replaceing the ECU entirely) will result in all the readiness monitors being reset. By the time you drive far enough for them to click over to "ready" the light will be back. There is no way around it other than having a tuner shop reflash the ECU or fixing the problem.

 

GD

I guess I should clarify. I'm ok with the light being on. I'm also ok with whatever codes it may show. We don't have emission testing here, so that isn't an issue. My problem is the car is in limp mode, fairly powerless and uses lots of gas. I'm guessing it's not sensing a variation between the 2 O2 sensors and because of that triggered limp mode and is running from a base map for the 2.5. I have a small pocket code scanner and when I erase the codes they all come back in a 2 mile drive.

 

I'm going to dig into it a bit more this weekend. I grabbed the knock sensor from the 2.5 last night, but didn't have time to swap it out yet. I also came across a brand new 3 wire O2 sensor in the garage last night, so I'll just screw that one in and see if it clears the O2 sensor code.

It's that knock sensor.

AFAIK the ECU doesn't care if the O2 sensors are working or not. They won't cause it to go into limp mode. But the knock sensor will. These cars are programmed to rely very heavily on knock sensor input.

well in my experience it takes about 20 miles of driving in that particular case to re-generate the code.

 

 

--Damien