[tutti57]

A few more thoughts. If your cat is hogged out, the o2 should be oscillating like you would expect to see a front o2, after it's warmed up.

I don't trust the fuel trims because At idle, your total trim was like 18 (lean), but the a/f says it was 2.18v (rich). I'm not confident that the oud you used to get that info was correct though.

Let's only look at lambda for upstream and o2 for down. Pull a vacuum line and make sure lambda goes above 1.0 and o2 goes down to at least . 200. Then add propane and make sure they both do the opposite. This will tell us that the sensors are reading properly. Watch stft to see if you get correlating changes. Remember that the o2 has to be very hot or this won't work. The a/f heats up within a few seconds. If all of this looks ok then we can trust the sensors and the stft.

It looks like you already know that lean condition at idle that improves with rpms is a vacuum leak, very good. If we can trust the data we just checked, then use your propane or brake cleaner to spray around suspect locations while watching stft or lambda and watch for a rich spike. Graphing is ideal for this if your tool offers it. Not sure if this is how you checked for leaks before, but listening for a change might not work. I'd suspect an intake leak with your cylinder misses, but also pinch of the purge line and brake booster hose and see if you get changes.

If it's not a vacuum leak, you can swap coils, plugs, injectors to see if the problem moves, and while you have plugs out, do a compression test.

 

[TimT]

Great ideas. Will work on this weekend and report back.
I'll try to lean it out and watch lambda numbers. If it leans out, I'll drop the exhaust and see if the guy really did gut the cat or just drilled holes in it.

Bank 2 02 doesn't ocillate because I used a spark plug fouler to pull it out of the exhaust stream.

And, it is running rich.

Another thing is the engine falls on its face when shifting and there's a pause to rev it up.feels like a long pause to me.
Everything is pointing to a clogged up exhaust.

Anywho,
Thank you and the forums help. Iam a first time poster and hope it helps someone else.

 

[tutti57]

A few more thoughts and possibilities, ha, I've wondered for a while if an O2 spacer would impact fuel trims since Nissan does use the rear sensor for some fuel adjustment. If it's being tricked, I'm not sure how it will react. I don't know if pulling it from the exhaust stream has the same affect as good cat o2 storage capacity, if that makes sense? Let me know how it responds to those forced rich and lean tests I mentioned before. If it responds and how quickly it does.

The other thing is that a rich cylinder can impact the compression if that cylinder if the walls gets washed down with fuel. If you end up doing a compression test, you want to hold the throttle open, and make the needle bounce up about 4 times, but the important bounce is the second one. It should be pretty close to the final number. If you have any low cylinders, squirt some oil in the cylinder and try again. It could be low because of wash down. I've seen people replace engine because of this. Heck, I got my current car for a deal because it was thought to have needed an engine because of this.

 

[TimT]

Well,
The cat is definitely hogged.

Forced lean with brake booster line.lambda went to 1.3 and car stalled immediately. Then, just made a very small leak and was able to watch lambda run 1 to 1.15 without stalling out.Upstream 02 responded correctly and followed lambda.

Ran propane again across engine bay and seen no changes. Opened air filter and flowed propane in there. Both lambda and upstream 02 responded correctly.

Don't have a compression tester and iam sick and tired of removing the entire intake manifold to get to the coil packs and spark plugs.
Looks like there are 2 injectors per cylinder (wtf). That's the only thing I never changed.
Injectors were reading something like 2millisecond at idle. Unfortunately I can't read them independently.

Any other crazy ideas before I take it in for you injectors or sell it?

Again,
Thank you and the Nissan versa forum for letting me post and helping me out.

 

[TimT]

One more clue. When the car falls on its face when shifting and there's that 1 second pause to rev up from idle,
If I turn the car off and then back on, it runs perfectly fine for 3 to 5 minutes and then goes back to a turd.

 

[tutti57]

Only that there could be a restriction in the exhaust still, after the cat. That's why disconnecting the pipe before the converter is good. It eliminates everything after it too.

I'd move the injectors around and borrow a compression gauge from a parts store for free.

 

[Zanthros]

Fuel trims are not what you'd expect on nissans. You may not get any changes with them. They use what they call alpha value, but you need a scantool with enhanced data to see this pid, so you can use the rear o2 and the equivalence ratio or lambda pids, which are your a/f sensor. These dont use an O2 sensor in the front.

If this is only occurring during idle, I'd expect a vacuum leak, misreporting MAF, leaking injector, or compression issue. With the car fully warmed up, and misfiring, what is the o2 sensor showing? You can tell if it's a lean misfire (fuel) or spark by watching this.

You can also introduce a small amount of unlit propane into the intake and and see if the condition improves, which would indicate a lean mis.

You can put a vacuum gauge on the engine and see if you have a steady needle with 17-21". If it's bouncing around, you have a mechanical issue, like low compression.

Good advice

 

[mpardhal]

So, the solution was to change de coils using Nissan oem coils?

 

[MTCoorscan]

Well, had it towed to to the local shop, they couldn’t figure it out but they thought it was the computer. Charged me $150 and said it would need to go to the dealer because they can’t program the computer. Had it towed an hour to the nearest dealer. They said the Nissan’s do not like any aftermarket coils. I told them to go ahead if they thought it would fix it. Sure enough $1500 later and it’s running great again.
I would have never thought it would burn up aftermarket coils and pop the coil fuse within 20 miles.

Anymore, especially with imports, if you buy the cheaper parts, you're doomed. I just recently watched a vid from Scanner Danner where they went through 4 new identical aftermarket ICMs, each failing from onset. The question posed was "who is going to pay for all this lost time" because the mechanics shouldn't have to eat it, and the customer shouldn't either. Doesn't matter that the part is warranted and refundable. Untold hours of diagnostic labor are wasted due to inferior/defective products. Mechanics have little choice other than insisting OEM parts are used.

 

[BillHoo]

This is an informative thread. Thanks!

I have a 2016 Versa Note. 176K miles. New transmission and catalytic converter installed Jan 2023.

Had new fuel injectors put in around 2019.

Past week, I noticed a little roughness from the engine.

Just drove over 230 miles to NJ from VA. about 20 miles from destination, the engine suddenly got really rough, check engine light came on and smelled unburned fuel.

Stopped at the local AutoZone this morning on got a free code scan. Scan returned:

• P0300 Multiple Misfire Failures
• P0302Cylinder 2 Misfire detected
• P0300 Multiple Misfire Failures
• C1130 Engine Signal 1
• C1109 Vehicle Battery Voltage Abnormal

The guy at the shop thinks I should be able to make it home to my local mechanic shop.

I think, before I go, I'll make sure my battery electrolyte is topped off with distilled water. Maybe throw in a bottle of fuel injector cleaner too.

 

[itsgetnugly]

nobody mentioned EVAP system here in this thread. I had same symptoms. A bad evap canister in back or bad evap solenoid at throttle body can cause misfire. If the evap solenoid is stuck either in open or closed position that will cause a P300 code with other codes. And solenoid malfunction at charcoal canister (there are 2) will cause all sorts of codes as well.

 

[HondaSpecial]

** To anyone still dealing with p0300 issues. Here's how I fixed an 18' Versa. Car came in with a p0300 cel missing hatd at idle. After some diag of the basics, the problem with the car was the engine was not being grounded to the car. The original ground cable was in a harness and was longer good. To save costs for the customer we made our ground using 4 gage cable. To simply test if your having a grounding issue on your versa, using jumper cables only attach the negative clamp to the battery and attach the other negative clamp to the chassis of the car.( shock tower, frame rail. .

I highly suggest trying this first very quick easy thing to check that definitely gets over looked.

Hope this helps someone, lmk if it does !

 

[psychoseacap]

Hey HondaSpecial, I have been dealing with this issue for a while now.

Would you be able to describe to me the process of how you were able to fix this? Where did you run a new ground to and from?

This might be the solution I have been looking for as my 2013 versa has this issue and I have replaced everything that has been mentioned in this entire thread.

 

[amc49]

He doesn't even know himself, first he claims engine not grounded to battery but the diagnosis was done for CHASSIS not grounded, two totally different things..................BOTH need to be in place.

Post 51 similarly messed up claiming bad evap (purge) solenoid closed will run bad yet that is how engine runs 99% of the time. The post is well intended but messed up in the wording of it.

On previous page there was repeated talk of 'checking EGR' on cars which have no way to chebk them other than getting a tailpipe test. The EGR is metered by variable cam timing and if messed up you get codes for that instead. There is no EGR valve at all.

You have wasted your time and money if you buy aftermarket coils or crank/cam sensors for these cars, they are often weak enough new ones won;t work.