I have a 98 accord that has an occasional loss-of-engine-power problem in the first few minutes of driving. I'll be headed off down the road and the engine will progressively lose power and the car will slow down. I'll continue depressing the accelerator pedal further until it's floored, but the car continues to slow. Then, suddenly power returns to the engine and the car surges forward like a rocket ship and I'm slammed back into my seat! This behavior only lasts about 5 minutes, and then the car runs just fine. A couple of other details:

- seems to happen more often when the engine is warm - e.g. if i drive to mall, then shop for 30 minutes, then return to my car. It's less likely to happen on a cold engine.
- the car always starts and idles smoothly
- when the car is having the chug/surge issue, I can depress the clutch (it's MT) and tap the accelerator and the engine generally peps back to life. But as soon as i drop the clutch and load the engine back up... no power again.
- the engine has never actually stalled during one of these episodes

Yes, the CEL is on... it adds nice color to the dash - like xmas lights. I had it scanned years ago and I think the code was a bad o2 sensor. I've ignored it.

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1998 Honda Accord LX 4 cyl MT >150k mi

 

Ok, don't take any of this the wrong way. You've ignored a issue and now have something you don't want to ignor. Have the codes checked again-there may be more now- and fix those issues.

Then, after resolving the CEL issues, I have to ask about the other maint items, are they up to date. It really sounds like the car just needs a little attention-new filters, plugs, I think 98 still had cap/rotor/wires, MT fluid change.

 

I had the OBD codes scanned and came up with the following

P1259 - "VTEC system malfunction"
P0420 - "Catalyst System Efficiency Below Threshold"
P0401 - "Insufficient EGR Flow"

The car certainly has had routine maintenance - oil, plugs, spark plug wires, and air filter...

Regarding the P0420, this is a 12 year old ULEV car with the original catalytic converter. I've got to imagine the ULEV rating places some tight thresholds on that error code. What is the service life of the cat? Could this downstream component really have anything to do with the symptoms I describe? I live in a state that does not do emmissions testing and the car will pass state inspection with the CEL - so I'm less worried about this code if it has nothing to do with the engine performance issues I described.

The other two codes sound like they are perhaps more relevant to my symptoms... any ideas?

 

P1259 - How's your oil? The VTEC is actuated by oil pressure so low oil inventory can trigger this one. Otherwise, remove the VTEC spool valve from the head & clean it out.

P0420 - I kinda sorta buy what you're saying. Not completely sure... but if you can pass inspection... ?

P0401 - Look in the DIY section for something about cleaning out the EGR passageways in your intake manifold.

Are you sure it's ULEV? I thought those only came with automatic trans.

 

Your driveability issue sounds just like my driveablity issue when my O2 sensor needed replacing. My car only has a pre-cat sensor but it failing took a big toll on the smooth running of my engine. Replaced it with a new Denso sensor and the way the running smoothed out was nothing short of astonishing.

 

Did you resolve this ? I had the exact same problem with 98 accord for over a year. Now the car will idle but thats it. Cleaned egr replaced map sensor, coil,plugs nothing fixed issue but now it will not drive at all ?

 

mines been having the asme problem too, cleaning my egr valve didnt help it.
98 accord lx

 

Farfrumnormal, start a new thread, so it doesn't get confusing. Post any error code(s) found by scanner. Parts stores like autozone will do this as a free service.

 

For jaffadog...
You need to confirm just what we're dealing with. I looked through parts sites, and ULEV was not offered in the LX trim, and ULEV engines were always paired with automatic transmissions. You might have a swapped engine that doesn't match the ECU.

 

You're right, its LEV not ULEV.

I'm working on the P0401. I yanked the egr valve and it does not look too bad. This engine seems to have a single fairly large bore passageway from the plenum - cast into the intake manifold - there are not plates or ports to clean it out. From what I can see under the egr valve, I'd say it doesn't look too bad, in terms of carbon deposits blocking them off. I might try suck on them with a shop vac. Seeing more would require taking the plenum cover off, which looks like a chunk of work - has anyone done this? got any advice? The egr valve is electrically actuated, not vacuum. Is there a way to test it?