Newbie here.

[CDKJudoka]

Hey guys,

 

I just picked up a 97 Legacy OBW for a pretty good price. The only issue it seems to have is hesitation after it's warmed to normal operating temp. Before that it runs great. I have changed the plugs, fuel filter, cam and crank sensors, and the front o2 sensor, yet it hasn't changed anything.

 

Does anyone out there have any ideas as to what could be the cause? i did notice something about an ECU recall for these cars.

 

Any help would be great.

 

Thanks

 

Craig

[CDKJudoka]

Okay, I went to the local auto parts store and they pulled the following codes from my OBW.

 

P0136 - o2 Sensor Circuit Malf. (B1, S2) - This one is pretty self explanatory and will hopefully fix that hesitation issue.

 

P500 - Vehicle speed Sensor A Malf. - I will check the wiring underneath, as my speedo still works.

 

P1101, P1121 - Manufacturer Control Fuel Air Metering - When I searched this particular code it came back as a Neutral Safety Switch issue?

 

P1540 - Manufacturer Control Veh Speed Idles Speed control Aux Inputs. This one has me baffled.

 

Again any help would be great!

[kaz98gt]

if there was an ecu recall for this one, take it to the dealer and have them run a check to see if you're due for that. if you are, that'd be the first place to start, because then they'll give you a free one that might cure it.

[CDKJudoka]

Well, after looking under the car it looks like the front o2 was changed recently by the previous owner. The rear o2 looks like the OE sensor, but I wasn't sure if that would have any bearing on the way it runs.

 

I'll bring my car into the stealer to get them to check on the recall.

[CDKJudoka]

Okay, looks like there is no recall for this particular car on the ECU.

 

I think I have narrowed it down to either the TPS sensor.

 

I noticed that the hesitation and bogging happens after the car reaches normal operating temp, and it gets worse under load, like going up hill. It seems to be "governed" at 3K RPMs. I will try cleaning out the MAF and the throttle body to further TS.

 

Any other ideas out there?

[CDKJudoka]

After doing more research, I have found that this issue might have to do with the knock sensor picking up too much ambient sound. There was something involving moving the sensor to the HillHolder bracket and resetting the ECU. Either that or I need to either block off or replace my EGR valve.

[CDKJudoka]

Okay swapped out the leads and the ignition coil. It is still the same problem.

 

and the EGR whistles when it misses.

[CDKJudoka]

Does anyone make EGR block plates for the EJ25?

[CDKJudoka]

No Subaru love here?

[kaz98gt]

I'd help you out dude, but the only stuff I know about the EGR is that the valve on mine was plugged and was causing a whistling blow-by that was ridiculously obnoxious. but even then that wasn't what was causing it...and I'm running a 2.2 I've noticed hesitation when mine is cold too; you can't floor it or do anything stupid (not my doing, my brother constantly beats on the legacy ). I'd try the EGR valve because it's probably never been replaced and is cheap...easy to remove and inspect. If not...hmm. I'm gonna take a look at mine today.

[CDKJudoka]

Thanks Kaz. The EGR only starts working after ther car is warm, so that is the reason why I am leaning that way. I really just wanna remove it and block everything off like I have done in my DSMs, 240s, and other old cars.

 

Too bad replacing it is almost $300!!

[CDKJudoka]

Okay, I have another EGR on order, and I ordered a set of OEM wires, since I used a set of Autolite wires.

 

Next step after this may be to get a Neon coil, since I have a Phase I coil, and that appears to be a big problem with misfiring and whatnot.

[Jeepaddict]

I just bought and fixed a 98 legacy OBW this spring. As part of the fixing up process, I took the boot off the throttle body and liberally cleaned it, (throttle body), with throttle body cleaner. It was very dirty. I also followed the procedure to clean the idle air control valve. It is the subaru procedure except using the select monitor to check duty ratio of idle air control solenoid valve. I used throttle body cleaner where subaru called for top conditioner or carb cleaner.

 

1) Start and run engine until cooling fan comes on.

2) Hold throttle at 2,000 rpm.

3) Disconnect air bypass hose from air intake duct.

4) slowly pour 16oz oz of carb conditioner in the bypass air.

5) run engine for 5 min.

6) stop & re-assemble hose.

 

If you are checking things to insure smooth operation, you would be wise to check the idle air is not sticking.

[CDKJudoka]

I should check the IAC, but with the car running great when cold, but like crap when hot, I bypassed that.

 

I took it to have the codes checked and it had the two misfire codes, cylinders 2 and 3, 0136, rear O2 sensor code, and finally the camshaft sensor code. Now, the rear O2 doesn't look that old, but it looks like someone tried to eat the the heat shield in the driveshaft tunnel. I will have the car on a lift of Saturday to check the wiring underneath, since the turn signal/back up light fuse keeps blowing.