I have a 89 iroc 5.7 and i just added ZZ4 cam, vortec heads, scoggin dickey intake. The car has edelbrock headers and 3" all the way with to cats, adjustable fuel regulator (50psi), and the plenum is ported. Anyway on my first drive the engine light came on, code 13. I was in a rush and got a chip from turbo city. Well the same problem. idle and WOT is fine but part throttle cruise goes lean. so I am ordering an aldl cable and going to use my lap top to check out my BLM's and all that. could my o2 be playing games with me or is this problem common. Is my only hope going for it and DIY prom burning which scares me? And my final question is should I get larger injectors like the 24# svo? Any advice please?

 

is your 02 a stocker or is it a 3 Wire Heated?

 

Code 13, and recent engine work, sounds like a silicone poisoned O2 sensor. If it is, then you need an open loop chip for like 100 miles, and then put in a new sensor. Or use a couple used ones til things clear out.

 

The O2 is not heated but I plan on going to one. Which one should I get? I will also run the pants off it for a 100 miles or so. Then get a new heated O2. Thanks and I will let you guys know.