# 98 4cyl fronty, drivability problems, hesitation`



## redneck truck (Oct 4, 2004)

well, that's easy enough. truck is a 98 4cyl frontier, manual trans, and when the truck is hot, it hesitates, most obviously at lower rpms. sort of acts like i've let go of the gas, when i'm really giving it part to full throttle. so far, it's got a new fuel filter, cap, rotor, and spark plugs, and I thought i'd get everybody's feedback before i do any more than that. i'm never a proponent of throwing parts at a vehicle without first diagnosing the problem. it was also suggested that i check for codes, but i'm not sure how to go about doing that. thanks!

- Bryan


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## d3l0n6 (Feb 10, 2006)

I had a very similar situation with my last truck. It was a 97 tacoma and I replaced the same stuff in addition to the spark plug wires. Never diagnosed the actual problem but I found that premium gas made the problem go away. The only other thought I had was the igniter coils but they were hella expensive so I just used prem gas. If you hadn't replaced the spark plug wires that should be your next step probably. Also make sure your plugs are properly gapped. If they are improperly gapped it can make a noticeable difference in the timing and worsen the original problem.


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## redneck truck (Oct 4, 2004)

gap is correct, timing is correct, spark plug wires are in good enough shape that i can't justify spending $75 on new ones. on my f150, i had a problem with knock, idle, stalling, hesitation, and failing emissions, and a new o2 sensor fixed all of those problems. on my hardbody, an o2 sensor made it pass, improved the mileage, and got rid of the rotten eggs smell. i am pretty confident that one of the o2 sensors is the problem, but it is expensive enough that i really don't want to be wrong. i already wasted $40 on cap, rotor, spark plugs, and a fuel filter. what do you think?


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## benett (May 28, 2006)

Before you change anything else ..check the EGR system.. what usually happens is that the egr passages to each cylinder get clogged( one or several). after several get clogged the engine may throw a code Misfire #4 cylinder. 
It actually was not misfire plug, wire or the dizzy.. just 2 clogged passages that needed cleaning. Engine goes into a full rich mode and your truck hesitates and you get poor performance. Run a obd2 scan and check for a code.

May or may not be your problem but worth checking..

do a goodle search on nissan 2.4 #4 misfire or simialar query and you will find many threads that talk about the egr clogged passages.

example:
http://www.pirate4x4.com/forum/showthread.php?t=469530


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## d3l0n6 (Feb 10, 2006)

You can test the resistance of your plug wires to see if they need replaced if you have a multimeter. When I was having the problem with my tacoma I took my plug wires to autozone or oreillys or some place like that and they tested the resistance on each one. It was obvious when one had a much greater resistance that they needed to be replaced. You might try that but be sure you know the specs on the wires so they don't try to take advantage of you.


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## Atl Nissan (May 5, 2006)

benett said:


> Before you change anything else ..check the EGR system.. what usually happens is that the egr passages to each cylinder get clogged( one or several). after several get clogged the engine may throw a code Misfire #4 cylinder.
> It actually was not misfire plug, wire or the dizzy.. just 2 clogged passages that needed cleaning. Engine goes into a full rich mode and your truck hesitates and you get poor performance. Run a obd2 scan and check for a code.
> 
> May or may not be your problem but worth checking..
> ...


I agree, I had a smilar problem on my '01 frontier with the 2.4l. It was generally just running like crap for a long time and it kept throwing misfire codes and even the dealer couldn't figure it out (way to go Nissan). I just learned to deal with it, since it wasn't all that bad, it just lacked power and I got pre-ignition if I ran regular gas in it. Finally, I took it to an independent mechanic and they figured out that an EGR passage was clogged. It made a world of difference, my truck ran like new again after that. My dad has the truck now and that was 60K miles ago and it still runs great. 

I tried everything, and replaced a lot of parts unneccessarily, trying to fix that truck but nothing worked, I wish I would have thought to check the EGR system earlier. It never crossed my mind. :loser:


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## redneck truck (Oct 4, 2004)

any details on how to clean the system?


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## redneck truck (Oct 4, 2004)

also, now that the check engine light is on and i have a P0500 code (vehicle speed sensor circuit malfunction), can the egr still be the problem? there is a technical service bulletin for that problem, but i cant find any info on it. anybody know what it might be?


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## azrocketman (Oct 5, 2005)

******* truck said:


> any details on how to clean the system?



Look at www.nissanhelp.com for NTB04-044 : http://www.nissanhelp.com/Ownership/Bulletins/Nissan/2004/NTB04-044.htm. I used Hoppe's #9 gun cleaning solvent and .22 and.45 gun cleaning brushes. If Nisssan would do the job for under $150.00 I'd let them do because it's a pain in the butt. 

Steve


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## redneck truck (Oct 4, 2004)

thats cool great info ...so what about the p0500 vehicle speed sensor code?


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