99blkt/a

So after installing set of O2 sims, I'm still throwing 420 and 430 codes. I've disconnected the battery, but don't know if that resolved the issue b/c I have an egr code that comes on immediately. Any ideas?

DVS99TRANS

iTrader: (7)

Do you still have the EGR hooked up? If so the EGR valve could be stuck or crapping out. That and where did you get the 02 sims from, didn't get them used did ya. The best thing would be just to get the codes tuned out. Putting headers on will change your air/fuel ratio regardless, most likely not as bad with mid length headers. A tune is normally the best way to go in my book. And how long did you leave the negative terminal disconnected. I have seen that it can take up to 4 hours to flash the PCM properly on both of my cars even though everyone says it will normally do so in about 45 minutes or so.

99blkt/a

No the egr is disconnected. I left the car unplugged for about an hour and they were still there when I had it scanned. The sims are brand new