Bucking, Hard Cold Start Problems

[THELAW1]

since it got cool..I'm starting to get bucking at low rpm's and hard starts when it cold, I ran a code scan and got 41 and 91, I 've changed the IAB, ECT,ACT O2's, spark plugs, cap rotor, TPS, EGR sensor, cleaned the EGR and EGR spacer, checked tiiming, clean the MAF, still the bucking is there and the codes , even the brakes are a slight hard, but it runs fine when warm...what is I'm missing?

 

[Look Its Aaron]

Vacuum leak?

That is one thing that I did not see you post about. Get a can of carb cleaner or something like that, and spray around the engine bay. If the engine revs up a lil bit where you are spraying, you have found your leak.

Do you have a vacuum tester or vacuum gauge?

 

[THELAW1]

I don't have a vacuum tester, but I'll try the spray...

 

[Look Its Aaron]

Just spray around the intake, vac lines, charcoal canister, vac tree. When you start the car can you hear a loud suction? Like a whistle.

 

[THELAW1]

I spray carb cleaner around the firewall and intake , did'nt fine no leak, so I changed the air filter and the bucking is gone , but still have hard brakes and hard start's in the morning

 

[warmdye]

I'd clean the MAF since the airfilter made a difference.