engine specs in sig. When I first bought the truck 3 years ago I was getting intermittent code 44. everything was stock. I replaced the o2 sensor and not long there after I started getting a code 45 when it would idle for 4 to 5 mins. now everything engine wise is new. still same o2 sensor, new prom(custom from edelbrock). if it idles for 4-5 mins the code 45 comes up. also until the engine is warmed up if I get on it it will hesitate/bog. could the o2 be faulty and misreporting to the ecm that it's running rich and leaning it out too much when cold?

 

If it still did it after you replaced your o2 sensor that I doubt that is the problem. The ECM is using the o2 readings to determine a rich/lean. In your case a rich condition. I'd check the other information sensors for proper operation, throttle position sensor(TPS), idle air control(IAC) to ensure that they are functioning properly and not sending faulty information to the ECM. Also check your TBI itself, are the injectors leaking, are they bad? If you can check the fuel pressure, make sure its where it should be (9-13psi) maybe the regulator has gone bad and too much fuel is going into the motor. Are they the proper injectors? Maybe a previous owner put in beefier injectors but they went too far. I'm not totally sure but I think you should have 55lb/hr injectors on that motor. Your sig mentioned ignition upgrades so I doubt that something is wrong in that area but it couldnt hurt to check just to make sure.

nice looking motor :hail:

 

thanks for the info.. as for the fp regulator and injectors everything appears to be good.. I rebuilt the tbi unit last year and the fp and all is new. before I replaced the o2 I was getting code 44 which was lean.. aftwerward the code 45 started happening. btw I just passed emission test with the vehicle if that means anything.. although I had it nice and warm before testing.

 

Hmm, more info. It is possible that the o2 you replaced the other one with is bad as well. They aren't too expensive and it might be worth it to replace it again with a new one. Go for an ACDelco one then you know you're getting the right one and one that'll work well. If you've done it before then you have the tools and elbow grease to do it, I know getting mine off after 100k miles was, well, fun. One that's only been on for a year should be easier, I hope. :lala: