Novak Conversions Jeep Wrangler TJ engine mounts

P0201 intermittent help & advice

Flcnj94

Member
Original poster
Joined
Apr 25, 2023
Messages
25
Location
Florida
Hey all, I have an 02 Jeep TJ automatic giving me some trouble for a few months.

Started about 2-3 months ago when I randomly felt stuttering/misfiring-ish when coming to a stop at a light or stop sign, and it would remain as I initially hit the gas to get going again until I got the speed up a bit and then it would go away. No codes right away, it was intermittent at first, and then it happened consistently a few days and I finally got the P0201 and P0301 codes.

Hooked a noid light up to the injector1 cable and it flashed normally as it should. I thought maybe I’m alright electrically since the noid light lit up normally. I did not do any other electrical testing as I’m not well versed with electrical. I went ahead and cleaned the throttle body & IAC, reset the pcm, and the problem persisted but it wasn’t throwing codes right away. I then changed the injectors themselves and the stutter problem persisted minimally. It wasn’t shaking much when coming to a stop but it would sputter whenever I was taking off and then once I got up speed it was fine. I then changed the spark plugs and coil, reset the PCM, and problem seemed to go away for about 2 months.

Over the last month I’ve felt a tiny tiny sputter coming back when taking off from a start that goes away once driving above 10mph-ish, and it’ll usually do it a few times at stop lights until I’ve been driving about 15-20 mins or so and won’t do it again. This has been intermittent. No codes.

Then, yesterday, as soon as I left my driveway and put it into drive, put my foot on the gas and immediately felt the sputter. Kept driving, it went away for a bit, and then about 25 mins in I got a CEL for P0201 and P031, sputtering and bucking a bit at a stop, when taking off, and at one point even when up at 45mph. I’d throw it in park at the stop and everything would feel fine until I hit the gas again and the sputter came back. Then I’d drive and it would seem fine from 15-35mph and if I got closer to 45 it started feeling shitty again. Not sure if the mph mattered or was just coincidence. CEL stayed on the whole time home.

Parked in garage & erased codes. Fired it up today and as soon as I pulled out of the driveway in drive it felt sputtering and the CEL for P0201 came back on immediately.

At this point, what would you do? Does it seem like an electrical problem? Could it be a sensor causing these problems? Am I better off taking it to a trusted local jeep garage and letting them figure it out or is there anything you’d immediately try first? I’m moderately capable of basic things, but nothing major or electrical.

*The only other thing I’ll say is since I’ve owned it, I’ve felt a slight bucking at 45mph intermittently where the rpm’s will bounce a bit almost like the trans is slipping especially on a straight away if I keep that constant mph, but it usually goes away above that speed or below it. So not sure if those are related I figured it was a trans thing I’d have looked at eventually because it’s been 2 years of that particular issue. Not sure if these are related but any advice is helpful! Thanks!
 
Hey all, I have an 02 Jeep TJ automatic giving me some trouble for a few months.

Started about 2-3 months ago when I randomly felt stuttering/misfiring-ish when coming to a stop at a light or stop sign, and it would remain as I initially hit the gas to get going again until I got the speed up a bit and then it would go away. No codes right away, it was intermittent at first, and then it happened consistently a few days and I finally got the P0201 and P0301 codes.

Hooked a noid light up to the injector1 cable and it flashed normally as it should. I thought maybe I’m alright electrically since the noid light lit up normally. I did not do any other electrical testing as I’m not well versed with electrical. I went ahead and cleaned the throttle body & IAC, reset the pcm, and the problem persisted but it wasn’t throwing codes right away. I then changed the injectors themselves and the stutter problem persisted minimally. It wasn’t shaking much when coming to a stop but it would sputter whenever I was taking off and then once I got up speed it was fine. I then changed the spark plugs and coil, reset the PCM, and problem seemed to go away for about 2 months.

Over the last month I’ve felt a tiny tiny sputter coming back when taking off from a start that goes away once driving above 10mph-ish, and it’ll usually do it a few times at stop lights until I’ve been driving about 15-20 mins or so and won’t do it again. This has been intermittent. No codes.

Then, yesterday, as soon as I left my driveway and put it into drive, put my foot on the gas and immediately felt the sputter. Kept driving, it went away for a bit, and then about 25 mins in I got a CEL for P0201 and P031, sputtering and bucking a bit at a stop, when taking off, and at one point even when up at 45mph. I’d throw it in park at the stop and everything would feel fine until I hit the gas again and the sputter came back. Then I’d drive and it would seem fine from 15-35mph and if I got closer to 45 it started feeling shitty again. Not sure if the mph mattered or was just coincidence. CEL stayed on the whole time home.

Parked in garage & erased codes. Fired it up today and as soon as I pulled out of the driveway in drive it felt sputtering and the CEL for P0201 came back on immediately.

At this point, what would you do? Does it seem like an electrical problem? Could it be a sensor causing these problems? Am I better off taking it to a trusted local jeep garage and letting them figure it out or is there anything you’d immediately try first? I’m moderately capable of basic things, but nothing major or electrical.

*The only other thing I’ll say is since I’ve owned it, I’ve felt a slight bucking at 45mph intermittently where the rpm’s will bounce a bit almost like the trans is slipping especially on a straight away if I keep that constant mph, but it usually goes away above that speed or below it. So not sure if those are related I figured it was a trans thing I’d have looked at eventually because it’s been 2 years of that particular issue. Not sure if these are related but any advice is helpful! Thanks!

Your symptoms seem to point towards a potential problem with the injector circuit or possibly an intermittent electrical issue.

Here are a few things you might consider checking:

Check the Wiring and Connectors
Sometimes, wires can corrode or connectors can get loose. Inspect the wiring harness leading to the injector and the connectors for any signs of damage or corrosion. A loose connection could cause the injector to not perform properly. I can't stress this one enough!

Fuel Pressure Test

Since you've already replaced the injectors, it might be worth checking the fuel pressure to make sure it's within spec.

Check for Vacuum Leaks
A vacuum leak can cause a rough idle and poor performance. Using a smoke test can help identify hard to pinpoint leaks in the intake manifold or vacuum lines.

Crankshaft and Camshaft Position Sensors
These sensors can sometimes cause intermittent issues like the ones you're describing. If they fail, they might not always throw a code right away, so it may be worth checking the voltages and making sure they are within spec per the FSM.

Consider Engine Grounds
Poor grounding can cause all sorts of electrical gremlins. Make sure the grounds are secure and free of corrosion.

As for taking it to a shop, if you’re comfortable tackling these checks, it could save you some money. However, given the complexity of the issues and if you don’t feel confident in diagnosing electrical components, having a professional take a look might be the safer route, especially if you suspect the electrical system's at fault.

Good luck, and I hope you get it sorted out soon! Let us know what you find.
 
Novak Conversions Jeep Wrangler TJ engine mounts