Honda MGR

Hello fellow forum readers,

I am new to this particular forum and I hope I can get some help with the issue I have with my Honda.
I own a 98 Accord with the J30A-1 V6 engine. I bought this car used and it has been running consistently well for the past 4 years. However about a month ago a mechanic performed an exchange of crankshaft seal and problems started to show up.
Right after he finished the job and we turn the car on for testing, the Check Engine Light (CEL) turned on. we thought the Oxygen sensor was unplugged, but actually everything was in its place. We had the car scanned in another shop and the scanner diagnosed Oxygen Sensor, as I repeat, everything was well connected.
The problem persisted and I took the car to another shop, where I was told the car had problems with the Vtec system, the scanner showed Vtec 1 and Vtec 2 fail.
At the same shop I got replaced the distributor cap, spark plug wires and new plugs and nothing so far. Every morning when I start the car (cold) the CEL is off and the car runs super smooth, but when the temperature gauge starts to reach the middle and the car starts to warm up, the CEL turns on and the car changes its response. It becomes much more slower it takes time to accelerate, once it passes 3250 RPM's it stalls.
I especially bought this car because of the V6 engine, nevertheless, now it feels like I am driving a 3 cylinder engine car.
Could you please advise in your own and better expertise than mine, what can be wrong with the engine?. By the way oil changes are done on time and premium gas has always been filled.
Thank you very much.
Manny

cschlick

if the code says an O2 sensor is bad then change the O2 sensor, they do go bad, alot.
its not uncommon for them to work fine cold, but not at all hot, and vice-versa

cschlick

also the reading off the O2 sensor tells the engine how to adjust the fuel-air ratio to maintain optimum performance, and emissions. that ratio needs to be different cold than it does hot. if the computer cant correctly adjust the fuel trim, then the engine will either run rich or lean and run like **** either way, too rich and you will foul plugs, get horrible fuel economy, poor throttle response, and burn out sensors, too lean and you will stall, burn out sensors, fry plugs, and run the risk of melting pistons or worse.

Honda MGR

Thank you very much for your response. However I do have two questions. How many O2 sensors are in a 1998 Honda Accord with th J30A-1 (V6) engine? If there are more than one, where are they located?
Thank you very much.
Manny

Lost Again

That is because of "open" vs. "closed" loop. Simple terms, the O2 is "along for the ride" until the engine temps get to a set point.

OP- Get the actual code(s). Guessing ends up costing too much.

cschlick

there may be as many as four, i would have to look to tell you, you should have at least 2, an "upstream" located on the exhaust just before the cat and a "downstream" just after the cat

you may have 1 or 2 for each bank i don't know anythign about that particular exhaust system

h0p3l355dork

There are 2. One before the cat and one "after" or in it technically. Are you getting a P0420 Catalyst below efficiency code? That usually means the cat is bad and might need replacing. But by all means, try the O2 sensors first. THey are about 150 each rather than 500-600 for a new cat.

cschlick

if youre paying $150 dollars for o2 sensors you need to fire your parts guy.

bosch o2 sensors are 49.99 for the upstream and 57.99 for the downstream, thats from autozone, you can probably get them cheaper online