93 Ford Escort with Rough Idle and not-so-peppy accel

Hi, I have a 93 Ford Escort, 5-Speed 1.9L. It idles rough, with a steady drop in RPM followed by recovery. I've replaced all the general maintenance items (plugs, wires, filters, etc) and it didn't make a difference. Also, the check engine light does come on, but not all the time and it doesn't stay on either. Seems mostly to come on at high speeds, though not always. It also seems to accelerate slower than my previous escort (same year, model), though I could just be remembering incorrectly.

I just ran EEC diagnostics on it and it gave me a "Fuel system at rich adaptive limit at partial throttle/system lean (181)" code, a "Fault in injector pulse width circuit/high (186)" code, a "EGR sensor circuit voltage lower than expected (326)" code, and "Cannot control RPM during KOER low RPM check (411)" code. I'm thinking the last one is just saying that it can't control the idle, though maybe not? This being my second escort, I'm familiar with the MAF problems it can have and have read in previous posts that a bad MAF can throw a "lean" code, but I didn't get any codes for the MAF specifically. Any suggestions as to how to proceed would be greatly appreciated. Thanks!