2003 Buick Rendezvous misfiring, sending no signals/codes. What could it be?

Did you change the spark plugs and wires also? Check the throttle plate(butterfly) if its dirty clean it with carb cleaner. They get a film built up on them and can't close all the way. So on cold starts when it should be closed it can't because of the film on the throttle plate.

No, plugs and wires haven't been changed. I'll try these things and see if it helps! Thank you :)

No problem. Good luck!

Well its not the plugs and wires. Those are brand new.. My dad is actually my mechanic, and he replaced those the last time we did a coil. And throttle plate is clean :( With it not throwing a code, i dont want to spend tons of money just replacing things

It could be the crank sensor, cam sensor, throttle position sensor or even the ECM ect.

ECM is brand new that was one of the first things we replaced. The crank, cam and throttle would those make it to where it misses while driving? I've gotten to where we go and warm the car 30 minutes before we drive it so it doesn't do the jerking/misfiring and it runs fine. But if we start it and go, theres always a misfire/jerking.

Also, reading about the cam senor i think it was, when all the problems first started the car would be jerking while driving and then shut off. But when we changed the ECM the shutting off stopped now it just jerks(misfires) if that makes sense

Did you ever figure it out? I'm having the same issues.

Yes, it was the hose next to the ECM. there was a hole in the hose and spraying the ECM. We didn't figure it out until we changed every last one of the plugs and wires and coils. Changed the hose finally and it stopped. Nothing since then and its been over 2 months. NOW if i can get my ABS an Traction to act right!

Your AWD light wouldn't happen to be on, would it? Mine has been on in addition to the issue you were having.

I'm having the same problem.. do you know what that hose was called that you replaced?

I'm not sure, I will have to ask my dad. I just know it was the hose right there near the ECM. As far as traction I've given up on that. Lol we've tried just about everything.

The abs and traction light issue ended up being the hub assemblies. I am now having the misfire issue which is how I ended up here. Lol Hate this suv.

In the 2002 Buick Rendevous they made the wiring too short to the wheel hubs and the wires break.I had all those lights on and after replacing the hubs need a special torque wrench which we rented.No lights and all repaired. I got all the hubs from detroit axle on ebay for 1/2 the cost of part stores and warranty for one year

So what hose was it causing the misfires?

Its only the mass air flow sensor its really easy its the same problem on all buicks

Its says misfire but is not