I have a 74 c10 with a 5.3. Been having surging problems ever since the swap was completed. It only surges when it gets warm and in park...never dies out though. My buddy who helped me with the swap checked everything but is stumped. However it does throw codes and they're all for o2 sensors..p0134,p0135,p0154 and p0155. I have already replaced the o2 sensors but the codes are still there. It has a new maf, iacv, plugs and wires, new fpr(engine is an lm7 from a 99 Silverado). Any input is appreciated. Its really annoying and frustrating so I could use any help I can get.
here's a video of it running...also has a small misfire issue...https://www.youtube.com/watch?v=4mDS...jQX1FLSq5DXMmw