have a 41 (c), what are the possible causes for this? Changed O2 sensor not long ago. Also have 44 (r)...AIR INJECTION inoperable? What do I look for here? the pump does work. Got it out of the shop 2 weeks ago cuz it wouldn't idle. Now it does idle, kinda ruff, and has an exhaust smell to it. Also seems to surge now and then. Shop cleaned fuel injectors, farted around with the egr, replaced vacuum thing-a-ma-jig (coffee can). When i first got it from the shop, the next day code 42 showed up..now it's 41...................
Thanks

 

It kinda sounds like an air leak somewhere. You had code 42, which says the system was running rich.
I’ve heard of a leak from the gasket between the top intake manifold and the bottom manifold.
I heard if you spry carb cleaner where you think the leak is the engine idle would rise, and you’ve found your leak.
Or the throttle body gasket is leaking, these gasket leaks would make it idle rough and I think make it run rich.
I’m not sure what the code 44 is but maybe you have a vacuum hose leak.
Its some thing to check out, but I’m sorry I could not help you more.