Equal Ninja

Well its fuel injected so i dont think that applies with the anti backfire valve. I just dont get why low RPMs when its cold outside would cause the hesitation, as i stated before if it gets warm enough outside it runs great through the entire rpm range. Does anyone know how to clean an EGR valve or what other subarus can i pull one off of that will work with my motor?

Hello everyone, im new to the community, just got me my first subaru the other day. Ive always been a big honda guy and ive been turning wrenches for about 5 years. Unfortunately where i live a FWD just doesnt cut it during the winter time so i got me a 4x4 subaru! I will get straight to the point. Got me an 88 subaru GL wagon, overall in good shape, has a few issues im looking to get a second opinion on. Car has 330K on it, leaks a small amount of oil, doesnt burn any oil that ive noticed. Overall it runs and drives fairly normal, idles good, gas mileage seems to be fair, always starts right up. Check engine light is on. I cleared the codes and re checked them. Ive got codes for an o2 sensor and the EGR. Previous owner said he had problems with the MAF sensor so i cleaned it with electrical cleaner just to be sure. While driving if the motor is hot or cold, under 3k rpms if i give it more than 50 percent throttle it hesitates and makes a pop sound under the hood (backfire). The colder it is outside the pop seems to be more violent and sensitive under 3k RPMS. Anything above 3k all the way up to redline seems to be fine at any percent of throttle When its warmer out side, like 35 degrees it sometimes doesnt hesitate or backfire at all under full throttle. Before i start buying parts for this thing i wanted some opinions. Appreciate the help guys.