When I get on the freeway my engine starts cutting out



My 1999, 1.6L, 4 cyl automatic Sentra has 209,000 miles. I commute from CA to NV every weekend. The car is not much to look at but the Transmission only has 10,000 miles on it, also the starter, water pump, and distributor are new. Now after about 20 miles on the I-15 the engine starts cutting out. The NV mechanic replaced the catalytic converter but the problem persists. In CA the mechanic has recently replaced my distributor twice. The second time was so soon that the part was under warranty–this must be some kind of flag. He has the car apart and can’t figure out what is going on. I need your help. It is not as easy as getting a new car, my wife has a lot of medical bills and with all the new parts how much more serious replacements could face me? I do not know anything about cars, but I found this show on the radio and think it is great. Any advice you can offer is greatly appreciated.


When was the last time the fuel filter was replaced???


And relatedly has anyone bothered to check the fuel pressure? This should be done under load.


It has been a good while. I’ll ask him to check it out, thanks.


Why was the cat replaced? Was there a code (from check engine light)? Or was it a guess?

Exhaust blockage is one thing that could cause something like this - but you can easily find out if the exhaust is blocked without changing expensive parts. Depending on how this all went down you might actually want a new mechanic.

The other most likely thing to cause this btw, is insufficient fuel pressure - i.e. clogged filter (if you’re lucky) or failing pump (if you’re less lucky).

The ignition system stuff (e.g. distributor) makes sense if it is heat related - but that should show up whether on the highway or not. That doesn’t mean its not ignition related - I’m just guessing about what I suspect are the guesses of your mechanic.


The mechanic told me the catalytic converter needed replaced after he hooked it up to his diagnostic equipment. He also said they dropped the exhaust and checked the rear catalytic converter for blockage without finding anything to cause the problem. I’m hoping it is something simple like the filter, but I haven’t been having a real streak of good luck lately. I really appreciate you taking the time to educate me regarding my Nissan.


I hope your weekend trips are not for the usual reason…


No, I head to Barstow on the weekend (usually to fight) to my wife. I spend my weekdays in Nevada.


Get all of the symptoms together. So far, there are only two, and they don’t seem to go together: 1. At freeway speeds, the engine starts cutting out; 2. The rpms go up, but my speed goes down.
Parts changed: distributor (twice); catalytic converter; other non-performance parts.

I don’t see why the distributor and catalytic converter were replaced, nor, even the distributor. There is not enough supporting information to warrant changing those parts.
We need more information about the: “rpms go up, but my speed goes down”. Has the transmission fluid level been checked?
Your mechanic seems to lack the necessary troubleshooting skills. The troubleshooting charts in something like www.alldata.com ($15 subscription). could be helpful to a mechanic (unless you have one who “knows it all”).

  1. The rpms go up, but my speed goes down.

I wasn’t looking at the tags for one of the symptoms. RPMS going up but speed goes down…means the tranny/clutch is slipping.


I’m not seeing in the post were anyone posted “2. The rpms go up, but my speed goes down”. Did I miss something somewhere? The OP only said about the engine cutting out.


It’s in the TAG …NOT the message body…Look just below the OP’s post.


Thanks MikeInNH I see it now! This old age is setting in! LOL


Well, its not just you. I didn’t see it either - but we still don’t have any idea what it means. Yet another problem description that fails to describe the problem. Why would something like that be in a tag but not in the description?


I have no idea WHY the op would put it there…I missed it the first time I read the post.