My car turns off when I stop and press the gas pedal

Hello, Welcome to Just Answer My name is \*\*\*\*\* \*\*\*\*\* I've been an automotive engineer since 1996 and together we're going to solve this issue. This could be an airleak after the airflow meter, any air dragged in here isn't 'seen' by the ECU and so not compensated for and can lean the engine out causing rough running. As its a mechanical fault it may not to turn on the fault light and you can sometimes hear a 'hissing' noise with the engine running. Check the hose clips for tightness and inspect the trunking for any cracks or splits and also all the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best way to locate a leak is to have the engine running and warm and then spray lighter gas /propane or brake cleaner around each joint in turn. If the engine rev's up you've found your leak. Now you might think that spraying lighter gas around a hot engine isn’t wise, however the flash /ignition point of gas is about 400°C so you need a naked flame or spark to set it off and I’ve used this method for many years without incident. Work your way through each possible joint one at a time and you should find it. I use a slightly flattened piece of brake pipe and some rubber hose from the can of lighter gas to provide a spraying 'wand' and allow a direct blast of gas into each area, especially those difficult to reach with large implements. Air leaks are very temperature dependent as gaps can open up as things expand with temperature so depending on how the leak occurs ( on a hose joint with a clamp expansion will help seal and on a vacuum hose expansion will make a leak worse) so leaks can be better or worse as the engine warms up 1 vacuum leak path that you won't find with the above test is if the brake servo is leaking so try clamping off servo hose to see if this has any effect It’s also worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a poorly pump will all result in insufficient fuel being delivered to the engine

I drive a cng carit’s not the idle control valve

This type of problem can be accrued due to different failures. We need to work together on it by elimination diagnostic approach, starting with the common issues: In your case, the problem sounds like you have a blocked [catalytic converter](/topics-catalytic-converter-honda/). That's the worst-case scenario. [Exhaust](/topics-exhaust/) build-up or exceeded exhaust fumes cant get through so giving it gas causes the exhaust to rush out but build up in the cads ...meaning very little exhaust getting through. Take out the secondary [O2 sensor](/topics-o2-sensor-honda/) the one leading into exhaust manifold then start for the car if it runs and they sound loud but if you give it gas and it sounds like your PM's and car revs up more than likely. Don't leave your o2 sensor unplugged flames to come through that hole so it can be dangerous too. please check it and keep me updated we will solve it.