Dodge Ram P0300/P0302/P0304/P0357

you are using a scanner - the Chrysler key on off trick will not show all codes. P0300 is a multi cylinder issue and you have multi misfire codes, the coil code is P0357-IGNITION COIL #7 PRIMARY CIRCUIT, and that would have us check #7 coil. Basics- I would start - plugs, appearance it tells a story - Wet, Dry, Black, Tan, damaged? OEM plugs are recommended, Fuel pressure test . Ideally a scanner to look at live data - akin to the old world Sun machines but faster easier. Look at ECT, Fuel Trims, Map, o2 sensor voltages get the complete code list. I think plugs will give a hint wher to go next.

I replaced all of the plugs and nothing changed. So, I replaced all of the coils. Now I've a whole new batch of wackiness. I can let it idle in the driveway but if I try to drive it around the block it will die when I slow down to make a stop. Engine light came on and I got a new code. P0202 (cylinder 2 fuel injector). I checked the connection and wires and tried again. I let it idle until engine light came on. This time is was P0357. WHAT? So I checked all the wires and connections on the new coils and tried again. This time P0500 (Vehicle Speed Sensor). OK. My head is about to explode. It seems to be cycling through these 3 codes now. P0202, P0357 and P0500. Where do I go from here? It's running rough, dies when you slow down, but if you can get a good idle speed it will run in driveway forever (Sometimes you can. Sometimes you can't). I'd scream but I don't know how to spell the sound I would make.

LIVE DATA------------------------------------------------------------------------- DTC_CNT 0 FUELSYS1 CL LOAD_PCT(%) 15.7 ECT(°F) 199 SHRTFT1(%) -19.5 LONGFT1(%) -28.1 MAP(psi) 8.0 RPM(rpm) 2165 engine wouldn't stay running. had to hold my foot on the gas. VSS(mph) 0 SPARKADV(°) 26.5 G IAT(°F) 140 TP(%) 16.9 O2SLOC B1S12--B2S---- O2B1S1(V) 0.820 SHRTFTB1S1 0.0 O2B1S2 0.880 SHRTFTB1S2(%) N/A G

Ok - I want to mention the brand and type parts used matter. How did old plugs look? You replaced 8 ignition coils ? Ca Ching $$$ Looking at your live data ECT is low - did you change Thermostat? Fuel Trims Are wack - way out. o2 readings support the trims .820. I suspect a leaking injector or injectors. confirm there is a fuel pressure test port (schraider valve ) on engine RS.

Replaced plugs with OEM Autolites from AutoZone. The old spark plug electrodes were very black. It was time for a change, I believe. The coils I got online at Amazon to save money. Autosaver88. $52. I did not replace the thermostat. I now understand what you mean about the trims. I had to do a little Googling on them and the O2 sensors. BTW: I want to thank you VERY much for your assistance and patience with me. I am learning a lot from you and am very grateful. Discover more coils vehicle Ignition Coil I will check fuel pressure and let you know. Hopefully tomorrow. Don't know if I want to deal with doing fuel injectors or not.

Here is my thoughts... hopefully there is a schrader valve on fuel rail. Attach fuel pressure gauge. Turn ignition to run - the pump will prime record high pressure, leave key on! - record pressure drop in 5minutes post PSI in 5 minutes. If you have not already - add a bottle of 'techron' or 'seafoam' fuel treatment.

Schrader valve: yes. Fuel pressure gauge: no. Went to AutoZone to borrow one but I don't have the $150 deposit they want. I was able to buy some Techron. It was on sale. I'll keep looking for a gauge.

OK. Located a fuel pressure gauge. Initial pressure with ignition on/truck not running was 42 psi. After a few minutes it was down to 38 psi. Started the truck and pressure went up to around 47 psi. After running for around 5 minutes pressure was still at 47 psi. Shut off the engine and waited about 10 minutes and pressure was still at 47 psi. Engine continues to sputter and shake and idle poorly. Been hearing a sort of deep toned rattle. When the truck sits over night it will start right up without even touching the gas pedal. But, after a few minutes it's back to Sputterville. Thoughts?

I forgot to mention: it's still throwing a P0357 code. Twice today. While I was doing the fuel pressure check and again just a few moments ago when I was letting it idle just to see what would happen.

"Shut off the engine and waited about 10 minutes and pressure was still at 47 psi" was the key in the ON position? THis keeps injectors energized. lets swap #7 coil with another cylinder - say #3 - see if code follows, coil issue OR remains as #7 even with the different coil.

I think key was all the way to off. I'll try it again when I do the coil swap.

Just did a quick pressure check. Same result. 42psi ignition on. Start engine and it goes to 47-48psi. Let it run 5 minutes. Turn off ignition and remove key. 20 minutes later still at 47-48psi.

Coil swap #3 and #7 completed. Ran for about 10 minutes before it threw any codes. New codes are P0202 and P0357. Cleared them and tried again for s**ts and giggles. This time we get P0354 and P0355. Yes, I'm about to pull my hair out. Idle still very rough (when it decides to idle) with lots of shaking and rattling.

Still no luck. Running as rough as ever and when I try to drive it, it dies. Still throwing the P0357 code, vibrating and rattling.

I have a 2002 dodge 1500 doin all the exact same things. I would love to know what’s caused he problwm

Start your own thread list codes.

I still have no answers. Took truck to the shop and they tell me I need a new timing belt/chain. I've hit a stand still as I just don't have the money to continue. Right now the truck mostly just sits. It will start right up anytime. I use it when I need to but I've no idea when it will permanently go ka-put! Updates to come.