Sputters Under Load When Warm

[DRH1998]

Hey all. I have a 1998 Chevy 5.7 and have had good luck with it up until this point. It sputters under load and idles a little hard sometimes. We have replaced plugs, wires, distributor cap, spider injectors and got to the point last night where we cut the cats off to see if that would make a difference, and it did help a bit but it still sputters under load and only when the truck is warm. There was an O2 sensor code but that’s it. Also is a pig on gas now

Any suggestions on what this could be is appreciated. Also did a compression test and it all came back good. The engine probably has 400k on it

 

[JohnZ71]

The engine relies a lot on the readings from the o2 sensor, do you know which sensor it is? The two front sensors control the mixture, pretty important. A faulty front o2 sensor can cause those issues

 

[L31MaxExpress]

The engine relies a lot on the readings from the o2 sensor, do you know which sensor it is? The two front sensors control the mixture, pretty important. A faulty front o2 sensor can cause those issues

The 02 code can be a symptom not a cause as well.

 

[Cadillacmak]

Hey all. I have a 1998 Chevy 5.7 and have had good luck with it up until this point. It sputters under load and idles a little hard sometimes. We have replaced plugs, wires, distributor cap, spider injectors and got to the point last night where we cut the cats off to see if that would make a difference, and it did help a bit but it still sputters under load and only when the truck is warm. There was an O2 sensor code but that’s it. Also is a pig on gas now

Any suggestions on what this could be is appreciated. Also did a compression test and it all came back good. The engine probably has 400k on it

Check your coil? Ohm test it to specs (you can find online) and see if its okay. If you stomp on the throttle at low speeds does the engine completely cut out for a second?

 

[DRH1998]

Check your coil? Ohm test it to specs (you can find online) and see if its okay. If you stomp on the throttle at low speeds does the engine completely cut out for a second?

It’s just super super laggy at slow speeds if I punch it. Takes 30 seconds before I get a reaction.